>>The house adapter kit sounds like crap to me and I thought the tuner would produce great sound with it.
I was not impressed either, playing our XM through the RCA inputs on an ancient boombox we have (of course it's hard to know which device is to blame).
FWIW I just saw in the Crutchfield catalog that Kenwood is selling a Sirius "home entertainment tuner" for, you guessed it, exactly the same price as Polk/XM ($299) as they continue to duke it out.
XM is a godsend traveling in Montana though, where you lose regular radio stations 20-30 miles out of town ... and of course towns of any size are 80-100 miles a part
In the mountainous areas, conventional radio is lost intermittently/sooner.