I tend to stay away from wireless after having problems with 3 different ones. My two companions this summer on the TA used Ascent Delta V's from Performance and they were awful. You had to remember to turn them on every time you started and they went nuts around power lines, neon signs, and electric fences. If parked near a neon sign they some times registered quite a few miles while parked. I also had a Cateye wireless model that didn't work out (I forget which model), since that I just buy wired.
I am sure some wireless models are fine, but I have given up on them.