Like someone else already said, the idea is great but the execution not so much. I'm going to say pretty much the same but from a bit different point of view.
That other person said that the mechanism is stiff. This is only partially true because of why is that. And it is like this because it's overengineered. This is high quality product where the quality became one of its weaknesses. It works stiff because of it's insane tolerance levels and it being made of metal it sufferes from slight flexing. The cavity of the guitar never being perfectly planed (especially after being painted with electric paint) which, if screwed too well, causes the unit to flex and those super slim tolerances then become zero making it very hard to change positions. The only remedy to it is to play with screw tensions so it becomes absolutely flat. Then it works super easy.
As for the screw changing positions.... can't say much but true it's not stiff enough and it wouldn't suffer from having a lock screw or something...
The problem with the screw touching the block and touchpoint becoming resonanti is a true thing and only remedy to it is to raise the spring tension.
Another problem, not apparent with the usual setup is the fact that the unit itself (baseplate) is 2mm thick and screws are not flat tops (have small bulge) which make them stick almost 3mm up. If your springs lie pretty low (close to the bottom of cavity) the springs will definitely bite with screws. I had to recess the cavity by 2mms to accomodate for that.
I agree that this unit could only be used with D-tuna or something when you have to resetup guitar if you want to go back to regular FR operation. Although, I'd recommend using a piece of wood as a shim which you can have virtually for free.
This unit is heavily overpriced. Half of what is currently retailed for is too much, let alone regular price.
