Sirius sent up out a Sportster Replay unit, car kit, home kit and Sportster portable boom box.

XM sent us a SkiFi II receiver and 2 car kits.

We installed the radios in our vehicles and we headed out on a 11 day trip to Utah.   On the 10 hour drive to Las Vegas, we started to develop favorite stations.     Both Sirius and XM have a lot of similar channels, channels that play country, classic rock, news, comedy and so on.   Now don't worry about wondering what you are listening to, as both units display the artist and the song name right on the screen!   This was a feature that I really liked, as I never know what the artist and song title is!

The biggest difference between the two units is the programming.  That being said, it makes things really hard.  What is good music to one may not be to another, its really just personal preference.   Because this is such a subjective matter, I am not going to say which unit I personally (or any of the other testers for that matter) liked more when it comes to programming.   I found that there were stations on both that I really liked.  Sometimes I like to listed to rock, and sometimes I like to listed to country.   One unit had what I felt were better country stations, the other had better rock stations.   This is one thing that you will have to figure out for yourself!   The only thing I will say about programming is that everyone seemed to like the comedy channels!

The basic functions of both units were easy to figure out.   They both had their differences, and things that work on one unit may not on the other.   One thing that was commented on during the test was the ease of using the unit at night.   Below are pics of both units during the day:

Here you can see what I am talking about.   The buttons on the Sirius (left) are still readable in the dark.

When it came to mounting the units into the vehicle, there were also some differences.  

The Siruis unit came packaged with the head unit (what you see in the above pictures), a 12v power cord, and a car cradle with a suction cup mount.   This was a great system, as it really let us just suction cut the unit to the window and go.   

The XM came with the head unit, 12v power cord, cassette tape adapter, car cradle and a few different ways to mount it.   One was by using double stick tape and sticking the car cradle to the dash.   The other was a vent clip that let you hang the cradle by your car dash vent.   While the double stick tape would work, I didn't want to stick the cradle to anything.   The vent clip also worked, but I could not get the unit out of the way of some of my vent controls.   I was also worried about it getting bumped there and damaging my vent.   I ended up fixing the problem by going to Ebay and spending $20 to get a suction cup mount like the Sirius unit.

If you are going to be moving the units around, I felt that the suction cup mount was the way to go.

To get the units to play in your vehicle, you have a few different choices.   Both XM and Sirius have in the dash units you can get, and you can buy aftermarket stereos that pick up satellite radio also.   You can wire them into the back of your cars existing stereo, plug into a front input if you have it, or just tune your FM radio to a preset frequency and listen.   Both Sirius and XM have FM Modulators.   This means that you pick from a number of FM stations, finding one that is not used in your area and the head unit broadcasts to your existing car stereo via your FM radio on that frequency.    We used this feature and were happy with the results.   On a side note, we found that while on the trails or on the road if we were close enough (within a few hundred feet) we could all listen in.   

In addition to the FM modulator, the XM unit came with the cassette tape adapter.   With this adapter, you pop the "cassette" into your stereo and the XM is fed through your speakers like you are playing a tape.   This method gave us excellent sound quality.   We all agreed that it was better than using the FM modulator.

Because the units were being passed from car to car, we didn't always install them properly.   Instead of putting the antenna up on the roof, it was just put on the dash board at the base of the front window.   While this worked fine for the most part, it did lead to a few interesting discoveries.

In the morning when I drive my kids to school, I always drive the same route.   With the XM in the car and the antenna just thrown on the dash there were no problems in the morning or afternoon driving this route.   With the Sirius in the car, antenna also on the dash in the same spot (in the edge of a defroster vent so it didn't slide around) it was fine in the morning.   In the afternoon it would cut in and out.   Why?   Both companies have different satellite setups.   XM has its satellites in geosyncronus orbit, meaning that they are in one place in the sky all the time, they don't move in relation to the ground.   Sirius has its three satellites in an inclined elliptical satellite constellation. Sirius says the elliptical path of its satellite constellation ensures that each satellite spends about 16 hours a day over the continental United States, with at least one satellite over the country at all times.   Here is another way of thinking about the two different satellite setups.   Think of it as a large flashlight shining down from the sky.   If it is always in the same spot, then the shadows will always be in the same place.   If the flashlight moves, then the shadows change, so you don't know where the dead spots will be.   In order to help with these dead spots, both Sirius and XM have installed ground repeaters in some locations.   When we installed the units correctly, with the antenna on the roof, the Sirius unit did not have any problems.   

Finally, I decided to see how both companies were when it came to the customer service department.   On thing I like is when I ask a question, I get a answer.   I don't care if it is a pre-done (canned) response, as long as my question is answered.   On November 7th, at 3:10pm I send this question to both XM and Sirius customer service:

Can you tell me how many total channels you
have, including a breakdown of how many are
music, sports, talk, news etc.?

Thanks
Pete

I did this because I wanted to gauge their customer response.   Both forms are almost identical, and I used the exact same information in filling both out.   In this case, I said that I was not a current subscriber.

Within 5 minutes, I received these responses from both Sirius and XM:

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I went out on the internet and tried to find out all that I could about their satellites and ground stations.   Here is what I found about XM:

I quickly found this on Boeing's Web Site:

Then this was pulled from XM's own site:

SPACE SYSTEMS/LORAL TO BUILD NEW XM-5 SATELLITE FOR XM RADIO

Washington D.C., June 07, 2005 -- XM Satellite Radio (NASDAQ: XMSR), the nation's leading satellite radio provider with over four million subscribers, announced that it has awarded Space Systems/Loral (SS/L)a contract for the design and construction of its XM-5 satellite. XM's selection of SS/L followed an intense industry competition.

Construction of XM-5 will be completed in 2007. XM-5 is intended as a ground spare for XM's in-orbit fleet. Boeing Satellite Systems has built XM's three in-orbit satellites (launched by Sea Launch). Boeing also is completing the construction of XM-4, which will be available for launch in 2006.

"With the selection of Space Systems/Loral, XM broadens its industry base to include two major satellite teams with the capability to continue to provide XM with the highest quality and most complete signal coverage in the satellite radio industry," said Hugh Panero, President and CEO of XM Satellite Radio.

So we know they have at least 3 satellites in orbit, one backup on the ground and one on order.   When it comes to ground transmitters, I was not able to find out much.   I found a blurb in one news story that said that they are "also setting up a network of more than 1,000 ground transmitters, or repeaters, to relay the signal into areas that have obstructions like buildings or mountains that block the signal.".   In another I read that xm had over 1500 ground stations.   

While looking around, I even found an XM Radio forum:

http://www.xmxp.com/index.php

One of the threads there had a TON of technical info:

http://www.xmxp.com/showthread.php?p=1474#post1474

For Sirius I found this info:

Sirius Message board:

http://www.siriusbackstage.com/forum

List of Sirius Repeaters:

http://scb147.home.comcast.net/sirius_repeaters.html

Sirius has three satellites in a high altitude elliptical orbit over the continental United States. Sirius Radio says that each satellite will spend about 16 hours a day over the U.S., and that at least one satellite is over the country at all times. Sirius Radio also has a back up satellite standing by in case of any problems with one in orbit.

So now it has been just over 4 months since we have had the satellite radio setups.   Here are a few things that we found out during that time:

Once you have satellite radio, its hard to go back to the regular radio!   All of the people that over the course of the review had test units in their cars have signed up for either XM or Sirius!   I think that says something in itself.   Being able to drive long distances and never having to change the channel is awesome!   With the home kits that let you hook it up to your stereo, boom boxes and the car kits, you can take your music from home, to the car, to work.   

The prices of the head units are also getting really cheap.   During the after Thanksgiving sales, we saw quite a few different stores that had the units for free after rebates.

The one argument against satellite radio I have heard from a number of people is "why pay for something that you can get for free?"   Well, its quite simple: you cant get this for free.   What station do I tune my car radio to that has music without commercials?   What station do I tune to that will keep reception not only from town to town, but state to state without having to change the dial?    What station do I tune to for just pure, uncensored comedy, talk, news or sports?  There is none, only satellite radio.