One issue with the phone (that won't apply to the OP given where he lives) is that in the cold, the batter can drain really quickly. I've had my phone go from 50% down to 5% on a 1/2 hour commute in winter (about -12 degrees that day). Once the phone warmed up, it went back up to something like 35%, but had I been going for a longer ride, I would have missed recording a bunch of it. I don't doubt a cycle computer would potentially experience a similar issue, but it's easier to keep that fully charged as you're not using it for other stuff all the time. Plus, the longer battery life in general will counter this somewhat.