I've been happy with the tcu design. Have from silver to red. If they are placed well in a pocket, the swiveling can actually be ok, not walking but changing to fit new load vectors. I also give them a pull in the range of load to see how the placement works. In parallel sided cracks, I just sling them with 24" runners (or longer)

I do not like tcu's because of their tendencey to walk easily out of a nice perfect placement and the stems rigid design tends to cause this in vertical placements. Slinging it helps a bit but this uses up draws for nuts. I'd rather have aliens on any climb.

Have the whole set, but I would recommend buying only sizes #0 - #4. I wouldn't put much faith in the #00 (if it's your lead though...). That said, TCU's come off my rack on every route - love 'em. I've found the #3 and #2 to be the most often placed pieces on my rack (along w/ the #1 camalot, of course). Solid where many other cams would not fit or would not be ideal.

From time to time, if you don't have the most solid of placements, TCU's can walk. It's not unusual to have one walk deep enough that you'll need a nut tool to snag the trigger. To alleviate this, always use a longer sling when you know a shorter draw is pulled tight.

so far the've been working really well for me. i love them.

Smooth action, great placements and they have that snobbish air of gear supremacy.