So I've been thinking of picking up a used (or possibly new) inexpensive cycling computer. Just the basic stuff like speed, average, high, odometer, etc. I've noticed there's a bunch of basic units by companies like Bell, Sigma, Cateye, etc. They all seem about the same to me. Are they? Anyone have recommendations types they particularily like? Thanks.

Oh and on the ones that have GPS, are they normally used by mountain bikers - or are they good for roadies, too?