...in use, I think I've had three or four of them over the years. It can be a little troublesome to get them clamped down on the bar tightly enough to hold it in place if your bar has a lot of reach, so the one I installed was on a Cinelli Giro bar. The wedge thingie is aluminum, so besides the business about losing it, they can also break.

So if you do end up getting it and it has the wedge, lube it up really good with grease on the threads of the bolt that tightens the clamp and the clamp wedge sliding surfaces, and test the bar stability before you ride it. It usually feels to me like I am over torquing it compared to a regular clamping stem before I get the bar in there solidly.

In fact, this reminds me that I have a Mavic bar with very long reach in one of these stems that I've been meaning to replace with something shorter....but it's a lot of work and the thing rides OK as is. Mne have never creaked, but maybe I just don't hear it.