The info given in the SFS docs in these matters is next to unexisting; check out the site instead (can't remember url, it's in the docs somewhere).
I have to object to SFS being slow reading lot's of small scattered files. Thats due to people messing with prefetch settings without knowing what they're doing. Set prefetch to minimum setting and the problem will go away. You can test different prefetch values easily by opening/closing a window with lot's of icons and do C:Avail FLUSH inbetween. However, I admit that it sucks that prefetch can't be disabled anymore. And yes, even with minimum prefetch it's slower than earlier version w/o prefetch, but not to a degree where I'd call it sluggish.
Note that there's alot of nice tools in the SFS archive, like SFSDefrag, SFSSalv, SFSConfig, etc.
I consider SFS "commercial quality", no matter the authors claims :-)
