I installed a Cateye Mity on my road bike in 1993 or '94, and except for two battery changes since then it has been very reliable up to this year. This year the few rides I took on my road bike I noticed I had to wiggle the head of the computer to get it to read - I suspect there might be a problem with the connections or wires, and I prolly can't get parts for the 20 year old computers, though.

I did win a new Sigma Sport wireless in a draw at a mtb race this fall and I have that on my commuter bike. I ride my commuter bike through a nuclear waste dump twice a day and get no interference. I suspect the *ahem* affordable Bell computers aren't the same quality.