I just bought a HSS vest and really like it. But I do have to agree, the crotch straps are a little iffy. I just hooked the thing up on my porch and hung in it like as if I just fell to see what it was like. It definitely puts a lot of stress on the ol' boys. The SOP harness is angled at such a position that it doesn't put as much stress right there, but off to the sides.
I'm going to use it though, as I feel its still the best and easiest out there to get into. However, i'm making slight changes to mine. I am going to use the rope with the prusic knot that came with my SOP harness. Its a much better and easier hookup in my opinion. I also ordered a caribiner from HSS that will make hook up a snap once i get started up the tree.
Just my thoughts.