When slightly tightened, this biner is worse than a maple syrup bottle to open. When I attempted to return it due to the “forever in lock-mode” feature, the store said that that's just "the way the biner is" and that they had actually had a few other people complain about the “forever in lock-mode” feature as well (I had two, and they both performed the same).
The lock action is incredibly fast; spin the gate once and it can be locked, or opened. Because the gate action is so easy and can move so freely, it's easy to "over-tighten" (I use this term loosely) to make sure it doesn't accidentally spin open. Though I can assure you I tried many different combinations of tightening, I never found one I could trust.
Note: I had this problem if the biner had become loaded in any way, and it seemed to act up more in cold weather.