I used a set for about a year on an REI commuter I had. They worked well in all conditions. There are some drawbacks, though--they are heavy, and the cable connection point was often awkward to manipulate (read: kinda sucked when I got a flat).
I wouldn't turn down a bike that had them, but I'm not sure I'd seek them out. All things being equal, I'd probably prefer mechanical discs on a commuter.