My wife just bought (and is now neglecting <img src="http://www.catsailor.com/forums/images/graemlins/frown.gif" alt="" /> ) her new Aquata equipe harness. The quick release is hard to reset and if you use it you will lose the hook. Not a big deal if you absolutely need to get out of it but I don't know how expensive the replacements are. I am not sure how easy it would be to release under pressure either. BTW, a friend just bought a set of Dakine kitesurfing shorts with the harness built in and he absolutely loves it.
Watch me regret saying this but I don't think the quick release hooks are really necessary.