So, is there anybody else around that's been using one of these regularly?

I ask because mine's been coming loose a whole lot. As in, after about five hours' worth of cumulative riding, it literally starts unscrewing itself. I've tried really cranking it down, but that only extended it by a little bit. I'm not willing to go with Loc-Tite, because I know I'll want to take it apart sometime.

Or maybe this is why I don't see a lot of people talking about using it?

I run one and have the same problem. I never paid much attention to how long it takes before loosening but I have noticed every couple weeks (I don't ride much more than practice and actual race on on race day which is once a week for me). It's kind of a pain but I just got used to bringing the special wrenches along and making sure it's tight each week.

Hmm. It's definitely nice to know I'm not the only person it's happening to. But, since there's still the likelihood of user error here, I may have to pull the same stunt I pulled in the "American-made frames" thread/argument over on the Freestyle board and email somebody at Profile.

I'm hoping my cranks moving around like they end up doing (until I go "What? Not again!" and fix it) hasn't changed the inner diameter/tolerance for my BB shell the same way an ill-adjusted headset/loose forks can cause head tube ovalization.

You're talking about the cups loosening from the frame, or the arms loosening from the spindle?

If you use blue lock-tite, you should be able to remove the part. The red one is the one to avoid, that's the permanent one.