What sensor (encoder) to use for shooter?

[Pault]

We used an allen-bradley photosensor and put a piece of retroreflective tape on the perimeter of our wheel. Although we didn't have the time to actually use it in our code, we proved that it works to a reasonable accuracy at 5000rpm (there isn't any empirical data on how accurate that I remember, but for this application you can get a pretty big error without problems). I'd like to hear from a team that actually got to use one of these sensors in their code.