Polar is the decent, but because the watch has metal contacts with the handlebar mount, it cna be subject to problems. My SRM has never failed me, though time and time again, everyone warns about pressure washing them. Seattle rain is never heavy, and so I can imagine it being a problem (I lived there for three years). People on BF have said no probs with power tap in rain, but I have a number of teammates who frustratingly beg to differ. PT has had the most rain issues I have heard of. Ergomo? I really don't know, but being inside of the frame with sealed bearings, I would guess that you cant touch it with the rain, but that might be pure naivite speaking (writing). I-bike? No clue.