i recommend the delphi mifi XM radio , its like a big ipod, comes with car kit, home stereo kit, a portable antenna to listen wherever you want, and an available ghetto blaster to bring camping and such, works great , you can also store hours of music and replay back whenever, most other systems you need antennas and power, but this one has rechargable battery and can go anywhwhere, i listen at work and in my ice fishing shack, as for xm vs. sirus , main difference is sports XM carries all hockey games and all baseball games, sirius i believe carries NFL and basketball and CFL i think, both have comparable music channels , i find sirius beter for underground and alternative and XM better for country, and classic rock