I have been using the keyhole system for about 2 years on a Hobie 16, Nacra 6.0 and now on my A cat. I prefer it now that I am used to it. I have not ever bounced out of it. What I like most is not worrying about dinging the boat with hook. I would spring for the extra money to get the carbon kevlar spreader one not the plastic one.
If you wear rash guards over your gear, you will have to cut out a hole in the rash guard where the ball goes into the plate.

Eric A class US 28