XM vs Sirius Portable Receivers - What's Out There

I'm looking at getting satellite radio to use at home, in the car and to use with headphones when I'm on the go. I see there is a Delphi MyFi unit for XM and a Sirius S-50. Are there other portables out there? Any thoughts on these two? How easy is it to use these units for different functions, such as in the car, at home or at the gym, for example? What about sound quality?
I am new to XM. I cannot speak to the other options you are considering but I just purchased the Delphi MyFi unit 2 weeks ago. It is very easy to use and transfer from office/home to car. For the gym it would work fine as long as you are listening to the 5 hours of recorded music feature. As to the sound quality, it is certainly not CD quality. If you are used to hi end sound you will be a little disappointed. I was. My retailer (not a big box outlet) who I trust said that XM does have a little better bandwidth than Sirius. The other issue for me is reception. For home/office use, the antennae must face out a window to the south. That was a bit of an issue for me. Also, the antennae for the car seems less effective than the antennae for the office. Fidelity seems to be a bit worse for the car than the office as well. For me, I'm still happy with my unit as I was looking for continuous music for my midfi office system plus the portability for the car on long trips etc.
I cannot tell you too much about the hardware.....but......the reception for XM was much better in my car than Sirius. I still went with Sirius due to the programming. I would look at programming long before hardware. They both offer a free online trial. XM claims to have a deeper playlist.....in other words, plays lots of B sides and crappy songs......while Sirius plays the more popular tunes that I want to hear. Your mileage may vary.
I recently signed on with Sirius so I could continue listening to Howard Stern and am very happy with the inexpensive Starmate Replay.

The S50 is THE cool Sirius unit to get right now because of the cool design, small size, and 50 hour Tivo-like recording ability. However, I've read a lot of reviews online about quirkiness of this unit. It seems many owners have experienced problems with the unit not powering up immediately or having it turn off all of a sudden. I've also read that it doesn't stay seated in the car craddle when driving.

Also, although you can record 50 hours of programming it can't be done continuously. I think it only records a program in one or two hour chunks, so that a five hour Howard Stern show can't be recorded continuously.

Sound quality of satellite radio isn't something that would impress you if you used it as your source in a nice two channel system, but that's not the reason I listen to iTunes on my computer or my iPod either.

Whether you go with XM or Sirius, I think you'll enjoy the varied content and all the music channels.

You hit the nail on the head. I have both services and you could not have said it better.....

One note on the portable players. As far as hardware goes, Xm seems to be out in front on this issue. If your looking for a portable that receives live content on the go, you may want to wait until March. Xm has new players coming out. Pioneer is coming out with the Inno and Samsung is coming out with the Helix. Just from looking from pictures, they look very good. Much smaller than the myfi and with a color screen and able to record up to 50 hours versus the 5 with the mifi. Xm has one additional player coming out but will only receive live content only while docked.

I would be more concerned with the programming versus the hardware. Think cell phones, its mostly about the network. You can have a great phone but if the service is poor, the great phone become an expensive paperweight.

Hope this helps.
I understood that the sirius portable can't receive live feed in portable mode, just record when it is in the cradle and listen to the recorded content on the run. Is that true?
Maineiac, I'm pretty sure what you said is true. That's why units like the Sirius S50 are basically iPods when in portable mode.

Although I intended only to subscribe to Sirius because of Howard Stern, I did read a lot of forum threads addressing both XM and Sirius. I've read about reception problems for either service and have even found threads where people thought Sirius reception was better than XM. My conclusion is that a lot of that could depend on where you are in the country. Meaning that your proximity to the satellite in your reception zone could be a major factor whether you get better reception with XM or Sirius.

I also wonder if satellite feed is handed off from one satellite to another within ones zone. The reason I say that is because every day around 11:30am my reception at work becomes poor and stays that way until midafternoon. Morning and evening reception at work is good, but the hours near lunch they aren't. I wonder if I'm getting my signal from a different satellite during those hours.

Kind of odd because I never have this problem with DirecTV. DirecTV gives you exact coordinates to line up your dish and once you lock in a good signal it doesn't seem to waver. However, with Sirius I'm only told what zone I'm in based on my location and that I need to orient my antenna east or southeast. Pretty vague.

Have you investigated any satellite radio chat forums? You may be able to glean some useful information there pertinant to your location and application. Luckily, the Sirius versus XM arguments are pretty tame and not like solid state vs. tubes, or the absolutely volcanic Valentine One vs. Escort rage sessions.
I have had XM for a looong time, I was in the first 30K subscribers and have had great luck. I have driven from Atlanta to Maine and back several times with excellent performance, with the only exception when riding next to straight up cliffs. A friend has the MYFI and he likes it except the battery life is not too good, reception wise no problem. I like XM because I am a big baseball fan and get to listen to every game.