I'm getting a chrony because we have had problems in the past... It's completely worth it because scars don't go away too fast.
Chrony brand chono's are great. The problem is that people get careless and then shoot the rear eye. After a few shots, the plastic breaks and ruins the chrono. I have seen two destroyed over a 2 month period. Make a wooden housing for it with Plexiglas over the top for the eyes. It works great and you won't ruin your Chrono. Chrony's come with metal rods and a plastic cover to shade the eyes on a bright day. This is only needed with high velocity bullets. With paintballs you won't have to worry about it. The Gamma model also will calculate the time between shots and can even connect to a printer. It isn't a BPS timer, it just gives you the time between shots and you need to calculate BPS yourself. The Alpha model can be picked up for about $80.