Personally, I prefer the wireless. I was always worried about snagging the wires back when I had one, and I'm too compulsive and paranoid to cut the wires. My current is a Cat Eye, but because of the HRM interference, I'm upgrading to a Sigma Rox 9.0.
I suppose that if I put a lot more use on the bike, I might get tired of changing batteries, but at my current levels, that's not an issue.