Both PFS3 and SFS are tons faster than FFS, PFS3 being the fastest. SFS has tendency to suck in some scenarios (say apps writing to multiple files at the same time, the SFS block allocator sucks here and gives alternate blocks one at the time generating mega-fragmented files).
When I tried SFS it exploded after copying 20GB data to freshly formatted partition. Perhaps it was somewhat unstable SFS version or something, who knows. I did't try again. To be fair, PFS3 doesn't seem to run stable for some, either. I have 320GB of data on PFS3 partitions here, and no problems.
