Great on a pulley
When using pulleys you cannot beat an oval krab. The automatic action on the Traict is smooth and simple to use whilst setting up. It also means that the insecure gorilla you climb with will not be able to tighten it to the point of no return. The only downside I see is that you really need both hands to operate the action. The lock can be twisted and opened single handed, with some practice, but it is not a simple affair.