I purchased a Cateye Mity 8 for my backup bike and an Astrale 8 for my primary bike. I like them both. Cateye is the brand my LBS recommends. I did not realize how valuable cadence was until I did not have it. I wish I had an Astrale8 on both bikes.
Some people have good success with wireless and other have not. Outside interference from power lines and bike lights are two principle sources of interference.