I've got one, carry it everyday. When I got it there was a TINY bit of unfiled metal on one side of the slot that the hand rides in. It was just enough to catch the hand and keep it from advancing the cylinder. Not every time, just once or twice every 50 rounds or so. Took it all apart and ran a little piece of sandpaper on that side; that fixed it up fine. Gave all the other innards a good cleaning and it works great. I did have the cylinder retaining screw come out on me, but I don't think I tightened it enough. Loctite'd in there now.
Just give it a good inspection before you buy it and it should be problem free. Pay close attention to the star on the extractor. I bought an 85 ultra-lite a while back that had a small amount of burring on the star. It ended up chewing itself up so bad the gun wouldn't lock up tight enough on one cylinder. Sent it back to Taurus and they fixed it, I just couldn't get comfortable carrying it again after that, so off it went in trade for a new toy.
I just put a crimson trace grip I got a deal on on Ebay, and I love the gun even more. Carry it in a manpurse/fanny pack on work days (can't carry inside) and a Don Hume J.I.T. whenever I can. Pretty accurate gun so far too.
BTW, this gun uses the same speedloaders as the S&W model 10..Convenient? I think so.