I ride without. I like the looks of the bike alot more, and I actually feel safer. Yeah, i know it's a pain having to glance back quickly, but i feel much safer looking and knowing whats there then trusting a mirror.
Their are times when i think, "ah a mirror would have been nice for that" but not often.
Also, Im on a fire dept and constantly around cops, not once have they noticed and or said anything. One of the times being when i got pulled over and was ina flame war with the cop, he looked at everything trying to give whatever he could, still didn't notice them. I think it's cause the block-offs now made look so sleek and stock that they dont think...ah, mirrors should be there.