Darko Nessie
This gadget oozes quality and even beyond what I expected in its versatility. It's very light and easy to move around the rack. I've been pretty happy doing squats with the travel platform but had no good option for pulldowns. I can -almost- get ass to grass using only squat wedges, but that's easily solved, especially since the travel platform's dimensions are no longer a constraint to using various heavy duty stools, blocks, etc.
My favorite aspect so far is using it for prone leg curls, and seated extensions look like an option too but I don't have a a rack mounted seat.
There is a tiny bit of play when using it for pulling movements, but it's nothing unexpected nor especially distracting. The shims are fine but kind of a PITA to use. Overall, very happy with it so far. It'll be interesting to see what creative options the community produces in the future.