After 4 or 5 installs, I've had mixed results. They've all locked properly and tuned well, and I expect they'd do that for a long time without issue. But, on two sets I had issues with the excess string cutoff feature which weren't entirely unexpected. When the high E reaches the cutoff point, rather than cut the string it folds over and wedges under the cutting die portion of the stationary outer peg. They were all new part installs so they weren't worn, it had to be excess clearance at the cutting point due to manufacturing tolerances. In order to make a shear cut on a string that's only .009" in diameter, clearance can't be any more than maybe .004", preferably less. Otherwise, the string is not going to cut - it'll just fold over and fill the gap.
If you call Planet Waves on it, they're good about replacing the tuner. Also, it's not the end of the world - the tuner is still a usable locking tuner. But, you have to back it up a bit and cut the string flush with the peg yourself, which sorta defeats the point of that feature.
The sets I installed weren't on my own guitars, so I don't know what the long-term behavior is with the things, but I expect that the cutting die will wear and eventually larger strings will start folding/jamming instead of cutting. Free replacements are fine, but changing tuners regularly shouldn't be on the scheduled maintenance list. It may be that the failures I had were flukes, but until I can get some assurance that this problem doesn't occur anywhere else, I won't use those tuners on my guitars.