I had the issue of a handle locking up which I've seen in multiple comments. Pfister quickly sent me a replacement handle under warranty, which was great. Easy enough to replace.

One thing you may want to try if you have the issue -- after I replaced it, I soaked the locked handle in warm vinegar for about 30 minutes, then rinsed well with warm water. It now moves really easily. I did not put it back on as I already completed the replacement, but I'm keeping it around as a spare in case needed.