I prefer the more traditional threshold type of rolling when a PC isn't actively being opposed. I like the randomness to be one-sided (i.e. on the PC's side) when they're trying to overcome an inanimate object, like a door lock. Inanimate objects rolling well to "resist" always seemed a bit goofy to me. A lock is a lock and the difficulty should be fixed rather than varying from one moment to the next. That's my preference anyway.
I can't remember the exact circumstances but I think we had a B&E expert with 10+ dice only get one hit with the 4-dice lock got four. One hit was an embarrassing roll, and statistically improbable, but it should have been enough.
