Mine cuts out quite a bit at my house off the towers. Only get EDGE there though. Pandora's even more finicky, I usually swap it over to my wifi connection. In 3G range I've never had it cut out though.
My slacker never works on edge or 3G. I try playing a station and it buffers then goes to genre list and freezes. On wifi at home it works fine, but I'd like to use it when I'm out.