Glenn S.wrote a review of Petzl William Locking Carabiner on June 9, 2017
Familiarity: I've put it through the wringer
I use screw-gate lockers for almost all of my locking carabiner needs (and primarily the Petzl Am'D), but I keep a pair of these for toprope or multi-pitch anchor master points. The extra-large basket allows for easy clip-ins of potentially multiple anchor pieces, and I like the triact auto-lock for piece of mind when the biner isn't easily viewable in a toprope scenario. Screw gates can come unlocked through see-sawing motion against the rock face; I've yet to see this guy even come close to getting accidentally popped. Yes, the triact is a pain to use, but for specific uses there isn't a better carabiner.