Speaking of signals and networks, that is another area in which Slacker does not disappoint. The clarity of the music is quite good and is on-par with a good digital radio signal in any well-populated area. Plugging it into your car's stereo will allow you to enjoy the same, or better, quality of music that you would otherwise, but this time the music is suited to you.
There is usually a short delay between songs as the new song buffers as to keep from skipping, but this delay is typically no longer than five or ten seconds. In addition to the delay, the free version of Slacker is ad-supported so you'll have to deal with a 30-second ad about every 10 songs or so. Compare that with your local radio station and I think you'll find that Slacker wins, hands down.