Digital radio is basically just audio like MP3 (they use the older MP2 format, but basically the same thing) If you have digital tv (Sky, Cable, Freeview) you can find most major DAB radio stations on there. My Dad has a DAB digital radio in his hi-fi that he uses and it seems OK, you will get data through, probably a little screen that displays what station it is, information on what the show is etc

As for the signal, I would presume that even in weak signal areas you'd get better 'reception' with digital radio than analogue, though someone else will have to comment on that.