I have it and absolutely LOVE it ! I'd never go back to regular radio.
I guess that if you need one all depends on how happy you are with your current radio stations. If you live in a big city with tons of variety, you might not need it, but if you're like me and live in an area where there's only one rock channel, one classic rock, a pile of country channels, and 2 of "Today's Hits", then you'd definately wanna get one
Not having commercials and seeing what song is playing is a great touch