I bought three Ultimate series OnGuard locks and I checked them last night. I had no problem opening any of them, and the keys, though small, seemed substantial enough to me. However, the keys for one of the three locks looked a little weaker than the keys for the other two, based on the amount of metal removed to form the 'cut' of the key, relative to the other locks' keys. And in fact, two of the three locks had a warning sticker on them that said the key needed to be fully inserted into the lock prior to turning. Apparently, OnGuard may be having problems with returns caused by partially inserted broken keys. Personally, I'd attribute this more to operator unfamiliarity with this type of lock mechanism and thus to operator error more than to flaws in the design. I didn't find the action 'rough', either; but rather, 'positive'. I expect the lock action will get a little smoother with use.