PFS and SFS are not that great either. PFS doesn't have (and never will have) a PPC native version so many don't feel it's worth buying for future Amigas. SFS isn't really finished (and looks like it never will be) and still has bugs and lacks some features (like locking drives). Either of them don't screw up often, but when they do, they screw up big time. Data recovery chance is approaching zero.
FFS is the only filesystem with guaranteed 100% compatibility whether you're running Linux-APUS or other exotic stuff. It's also easy to get the data out of a broken partition.
I'll stick to FFS on my SYS: partition for now. With a system as stable as mine (no hacks), I almost never get an invalidated disk - and that's when running Samba too! I run SFS partitions too (and can't say I see much of a speed difference), but I keep a very close eye on them...
THOR's DiskSafe is also a nice tool for FFS users that stops them invalidating their HD with a badly timed reset or even from some crashes.
