I have been using PFS3 since it was new. In fact, I have an early release or something because I have a PFS2 disk that has a PFS3 update on it.
I have had problems in the past, but I absolutely will not blame PFS3, as I guarantee I would have had the same problems with FFS. I am a programmer, and I didn't start out on the Amiga, so it took me years to get up to speed and even now when I first start a project theres a good chance it will take me a couple dozen harsh crashes before I have a stable version. Those harsh crashes always happen right after I have saved my source, and saved the new executable. So, hard drives get scrambled, no matter which FS.
DiskSalv is faster and more reliable than PFSDoctor. DiskSalv won't work under PFS, and PFSDoctor won't work under FFS. PFSDoctor does work though. You have to be careful when you use it, and, always always log everything it does!
DO NOT EVER use the 'diskvalid' program that comes with PFS3. Always use PFSDoctor. Unless, there is a bugfixed version that I don't have. Diskvalid has cost me much data in the past, it tends to destroy lots more than it fixes!
The features of PFS3 like .deldir and rollover files are features I cannot live without!
I currently have PFS3 on a 100G hotswap SCSI3 drive. PFS3 does not like to hotswap! But, it is guaranteed not to trash such a drive (this includes drives that lose power during writes for whatever reason), unlike FFS, because when PFS3 encounters a problem, it immediately changes the drive to read only until you reboot.
My other PFS3 drive is a 50G SCSI3 RAID array. It works flawlessly. The only problem I have with it (and I'm sure this is the hardware's fault, not at all PFS3s) is that if I automount it, the system hangs. So, I have to have a seperate drive to boot, which mounts the RAID drive.