I love this 'biner. So much that when someone stole the first one I bought, I immediately got a replacement of the same. Plus, with the reduced price, you can't go wrong. The twist lock ensures that I'm always safe and keeping my partner safe. Just don't let it get you lazy and forget to check your setup anyway. I find that this carabiner is excellent for what I do, which mostly indoor/sport climbing. If you are worried because it is conceivable that the twist-lock could open up mid-climb, play around with one at a nearby store and you'll see how much effort it would take to accidentally rub up against it in a way that would release the gate. If youre still skeptical, and want an added level of security but still have the auto-locking properties, consider the Petzl William Ball Lock Carabiner, which requires a button to be pushed to release. As for the Airlock 2, I find it very solid and if it's used correctly for what it's intended for, and that's mostly belaying, it is absolutely reliable and I highly recommend it.