Winn makes great releases. The only reason I don't have one myself is the glove is too stiff for my liking.

The loop hook won't come off the loop. It is "grooved" so that the loop sits down in the groove right up next to the head and can't slip out unless you do some kind of contortionist stuff. It is the same release as the C-10 but with out the bar to enclose it. You still have to close it yourself but you go ahead and lock it closed long before you ever see any deer and being open like it is the "hook" slips right into the loop when you need it to rather than you needing to fiddle with it when you are trying to shoot a deer like you would have to do with the C-10.

I haven't played with the SS caliper because I don't like single caliper releases.