One more con:
- Difficulty of initially mounting

I have always used wired for cost, I recently bought a wired cadence computer and both speed and cadence mounts were on the left rear chainstay. Just this morning I battled it for longer than I care to admit, trying to get it mounted just right, figuring out how to take up the slack in the cables but make them reach as far as they need to, etc. It took WAY longer than it would have with a wireless computer. However, as others have said, for the most part it's a one time affair. I won't have to deal with it again.