[f5fstop]

A well written article, explaining the differences....
Depending on your interests and how you use radio, one satellite service will be right for you. Both services offer an enormous amount of great stuff and also lots of mediocre programming.

Despite the considerable overlap in programming, a handful of distinctions are so clear that you can base your decision entirely on them. Baseball fan: XM. Football nut: Sirius. Movie maven: XM. Howard Stern addict: Sirius. Bob Dylan freak: XM. NPR lover: Sirius.

If movie soundtracks are your kind of music, XM is the only service with a channel dedicated to those sounds, including long-form profiles and interviews with composers such as Danny Elfman and Randy Newman. On the other hand, if you want Playboy Radio or Korean-language programming, Sirius is your only choice.

Sirius has the only all-gay channel; XM, the only black talk channel.

As both services reach beyond the early adopters to capture a mainstream audience, they are looking to big-name celebrities to win new subscribers.

Sirius has staked its future on the uncensored Stern, while XM counters with bad boys Opie and Anthony. XM has built its version of public radio around former NPR "Morning Edition" host Bob Edwards; Sirius doesn't offer original programming of that kind, but does have the real thing, two channels of shows produced by NPR.

XM has signed Bob Dylan, Oprah Winfrey and Snoop Dogg as celebrity hosts. Sirius's stars include Martha Stewart, Deepak Chopra, Judith Regan and Mark Cuban.

But while both services vie for big names, the main attraction on XM (6.9 million subscribers) and Sirius (4.7 million) is the music. The tunes are often similar; how they're presented is the difference.

In their original visions, the competitors touted a world of musical choice unfathomable on FM radio; they promised all the formats that listeners enjoyed before corporate consolidation so greatly narrowed the kinds of tunes available on free radio, plus lots of niche formats never before heard on the air.

Sadly, however, that vision yielded to a more mainstream approach. And some of satellite's early experiments have already been pulled down from the bird. Both XM and Sirius killed their world music channels, eclectic mixes of tunes from every continent.

XM excised channels for cool cocktail lounge sounds, African pop and a free-form mix of exotica from across the decades. Sirius silenced channels featuring swing jazz, baroque classics, and tropical and calypso music.

Still, what remains is a selection far beyond what free radio offers. Both services have stations dedicated to the pop music of each decade from the 1950s to the '80s; XM adds the '40s and '90s. XM's decade channels sound like radio stations from those eras; it's a fun, cartoonish approach in which Top 40 hits are mixed in with old commercials, bits from TV shows, and deejays who adopt the style of the time they're re-creating. Sirius does a little of that but generally opts for a more contemporary, serious sound.

What Sirius lacks in fun, it makes up for in the quality and intelligence of its deejays.

XM subscribes to more of a jukebox model, providing long sets of uninterrupted music on many channels. The theory is that since song and artist names appear on satellite receivers' displays, most listeners just want the tunes, thanks. On Sirius's more highbrow channels, especially, announcers provide more background about the music than do the deejays on similar XM channels.

I've heard great storytelling about artists and their music on Sirius from pioneering New York rock deejay Vin Scelsa, whose "Idiot's Delight" is a rare satellite show that feels alive and intimate. Legendary jazz jock Les Davis and folk and rock host Meg Griffin also do shows that hark back to the era of deejay as tastemaker, educator and entertainer.

XM has compelling deejays, too, such as Jonathan Schwartz, the dean of American pop standards; and two voices who once defined D.C. classical radio, Martin Goldsmith and Robert Aubry Davis.

But Sirius gives its deejays more time to shine -- and more to fail, too.

For all the smart stuff you hear from jocks on Sirius's jazz and classical channels, the banter on its pop channels sounds just as inane as on too many FM hits stations.

In general, if you're looking to hear new music and understand where it fits in, Sirius is the place. If you'd rather the jocks let the music do the talking, XM's for you.