I've got an 8 year old Topeak Panoram that has never given me a lick of trouble. It's even on its original battery. It has been rained, iced and snowed upon countless times with no issue, even though it wasn't touted as being "waterproof". It has a wide screen that shows distance, elapsed time and speed all at once so I don't have to switch screens. The numbers are very large and easy to read. I wish they still made the model, as I'd buy one for all of my bikes.

My other bikes have Cateyes. They've been pretty good for me as well, although they only display one thing at a time. No water issues with them either, but those bikes don't see the weather as often as my main commuter.

I bought a cheap Chinese computer for < $5 through Meritline for my wife's bike. That one has been less than reliable. Likes to quit working or reset itself mid ride. And she never, ever, ever would consider riding in the rain.

Myself, I prefer wired because of one less battery and some reports I've heard from others who've had interference problems.