blocksize SHOULD always be 1024 !!!!!
anyway latest sfs is fast here , i get seek times under 100 and i get speeds upto 8.9 megs per sec on my olllld amiga 1200 with ppc + scsi.
but yes pfs3 is faster but also more intensive to the cpu..
anyway fix the blocksize and hehe btw in pfs docs it says 1024 block size! not 512 ...
good luck!