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.
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?