Carter Quickie wrist strap with a buckle (no velcro- loud and inconsistent anchor point if you don't fasten it in the same spot each time. I wouldn't consider a thumb release unless it has a wrist strap. Too much can go wrong and you will be 20' up a tree with no release.
I had a TrueFire Hardcore and I would have agreed with you. It had basically a weed guard thing on it, but you had to hold it in fear of it falling to ground. Very annoying.
I just got a Tru Ball Fang release that locks on the string and it has be wonderful. It has just become part of my routine: put bow hanger in tree, pull bow up, hang bow, arrow on string, release on string.
Don't have to think about it again until its time to shoot and your hands are free for binocs, range finder, whatever.
I shoot much much better with thumb than index finger. Better, more natural anchor points for me.