In reply to Otis:
> Would be interesting to know how it feeds out slack when you want to clip. Do you have to use the remote, or will it happily feed out at a slow pace? If the former them you'd need one remote on each arm!
I imagine you need to pull it through yourself. If it is using electronics it should be able to have low friction for pulling rope through and then actively brake the rope after a fall, it's got more flexibilty than a simple mechanical device. Probably less slack out than a mechanical device if the climber is actively pulling the rope thorough and potentially really soft catches if they get it tuned right and apply braking progressively.