newly formatted SFS disk is always faster than old empty SFS disk.
I have some vague memories about reading somewhere that some zones of the HD (when sectors are written at the borders) are faster than others -inner ones- (but I may be wrong)
BTW, nothing to argue against PFS3 vs SFS performance, I just hope it jumps to 64bit soon so we can enjoy bigger HDs and >4GB files with it too. I use ext2 due to big files and my partitions are formatted as SFS so I doubt I*switch soon-ish
