Sure, the styling on each is slightly different. Pioneer takes a traditional angular approach while Delphi and Tao go for more fluid design. But they're all about the same size and built by the same people: the remotes, batteries and cradles of each work on the other. Their user interfaces are identical.

That doesn't mean they're bad. For roughly $300 plus a monthly fee, you get an XM satellite radio for your home and your car. When you're jogging, provided you've got a big enough belt, you can clip it on, plug in some headphones and go. If you don't have much luck receiving satellite signal via the built-in antenna (and don't want to wear an external antenna on your head), you can set XM2Go to record up to five hours of XM on up to two different channels when you do have good reception, then play that back while you're jogging. It's not an iPod killer; it's just a unique, straightforward product capable of delivering on its promise, which isn't always the case in the portable audio space.

My problem is that the XM2Go template isn't perfect, so why clone it? I'm not going to point fingers, but it seems pretty lazy when there's a whole lot of work to be done. How about an improved user interface? From buttons and fonts to the very menu options, this system doesn't exactly scream out, "I'm perfect!"

More importantly, sound quality on the XM2Go could be better. When you finally hear the signal up close—like through headphones instead of a mediocre set of speakers—you realize there's a lot to be desired. Yes, partly the limitation is the satellite radio itself, which can't beam 128Kbps MP3s from the sky. But at least one XM product, the great-sounding Polk's XRt12 home tuner, was able to compensate nicely for satellite radio's inherent sound quality issues.

Finally, if they're all the same, why is the Pioneer $30 more? The answer is in the extras. The Pioneer ships with two antennae (a big clunker and a smaller one for the car) as well as a cassette adapter for those people lucky enough to still have cassette decks in their dashboard but not lucky enough to have built-in XM.

APRIL 21 UPDATE: My suggestion, that the Pioneer is more expensive because of accessories, turns out to be wrong. Both the Tao and Delphi models also ship with the full gamut of car and home adapters. The same product sold by Pioneer lists for $30 more only because of its highly recognizable—and trustworthy—brand. Thanks to Erden for pointing out my mistake.