My wireless friends don't have such horror stories if you exclude the occasional 100 km/h display, but they certainly eat more batteries than I do.

My wired commuter, a Cateye Mighty, has been running on the same battery since I bought it in 2002 or 2003. I run the wire along the brake cable so it doesn't look bad. Not perfect, but between that and the huge sensor/transmitter of the wireless systems, I'm not sure which is uglier.