Definitely worth getting a DAB radio. I bought one to plug into the Hi-Fi system, and another extra tuner thing for the car radio. I live in and travel around the Newcastle upon Tyne area and there are a few tiny pockets of poor signal. There's more choice on the new system.
The system works on the VHF Band III frequencies, that is what used to be for the 405 line B&W television band used by the commercial channels (ITV, Tyne-Tees, Granada, ATV, Thames etc.).
The audio is encoded using a method broadly in line with the MP3 system, and in its fully fledged stereo full-bandwidth is at least as good as if not better than comparable VHF FM reception, and has a better siganal to noise ratio. Some DAB stations (BBC7 for example, broadcasting speech and archive material) are mono broadcasts to conserve bandwidth, although a stereo version is put out on Freeview.
Planet Rock, Jazz FM, OneWord, and Smooth are welcome additions to the regular stations. DAB is the future for radio.