A friend has one of the standard hooks, with a quick relase mount, which sent him swimming when the release was premature.

I know it's not popular, but I use the seat only harnesses (no over the shoulder/neck kind), and feel I can quickly click out of it if my hook got snagged. Much harder to do on a full harness, with a limited breath, the forces of being pinned with a bouyancy device, etc.

Even in the long on the wire races (great TX 300), etc., I find my crotchless harness with the spreader bar very comfy.

But, I do think the ball and socket style is a GREAT option, with superior safety, etc.