Yep spot-on, I'll add: From a weight perspective, a well-sized D-lock used correctly should not have enough space to permit an attack with a jack, so don't get

Yep spot-on, I'll add: From a weight perspective, a well-sized D-lock used correctly should not have enough space to permit an attack with a jack, so don't get one that's too big. Also, one mistake chain-users might make is allowing enough slack that a link is close to the ground, which can be used as leverage with a bolt cutter, etc.