I haven't tried the Cobra release, but I have a somewhat similar one that Winn makes for string loops. It has a C-shaped clasp that you simply insert into the loop and pull back. It is very, very easy and ultra quick to use. My only concern is the noise it makes. When you hit the trigger, the clasp opens forward and the string slips off the release. I guess all releases so that, but due to the shape it seems like it offers more opportunity for the string to vibrate upon release. When shooting, with your ear near the string, it is noticeable. I haven't had anyone stand next to me yet to see how loud it might be a few feet away, though.

BTW - I've never had it even come close to coming of the string prematurely, which was a concern I had early on. Even when letting down, there is no problem.