I bought a handful of the early RBI's, as well as about 20 a couple of months ago...
I haven't had any problems with any of them... I have them in both rat and mouse tubs.
I don't have any complaints. On my mouse racks, I use a 1/3" wire instead of the 1/2", so the valves go on the bottom of the screen, with the tubing on top being the only thing that holds it in place. No problems with that on mine. Even with an occasional bump from a tub being pulled out, they are fine. On my mouse grow out rack, the tubs are only 3" deep, but even with that, I don't have any problems with the valve sticking all the way out on the underside.
ON the rat racks, with 1/2" screen, I did have a couple of times that they would pull it down and chew through the line, but I just took a cable holder, and screwed the line to the frame so they couldn't pull it down if it happened to get loose....problem solved.