Rich sent me the CFFA3000 Rev C board - here it is, running through its paces this morning:
It's at home in a GS with a 7-ish MHz TransWarpGS accelerator just now. SmartPort disk access is lightning fast, but of course the emulated Disk II is always at 1MHz speed. If you have a normal floppy disk image, you can get around that by naming your image "whatever.SPO" (The SPO stands for SmartPort ProDOS Order) or "whatever.SDO" (SDO stands for SmartPort DOS Order... the usual format for .DSK images) and it'll be mounted as a SmartPort device. That way, it bypasses the Disk II emulation, and goes at the fastest speed your Apple can handle.