I have never really given them much thought because I find I can wear my harness loose enough that I can move it around quite easy without it riding up and I didn't like the idea of a clunky metal on metal setup but the dyneema sounds interesting.
As far as snapping hooks goes on my first decent fly of my then brand new (several years ago now) 7.5mtr Bandit in very strong wind, I went to do a big jump transition and to my surprise at the top of the jump I redirected the kite and the hook snapped clean off my harness.
I was left dangling in the air looking at my hook swinging on my CL.

I crashed the kite and of course I was a long way out, went to self rescue and the sharp bit that was left on my harness where it had snapped punctured the leading edge......