It's ok I wanna know about Animal Crossing too, ambitious.
Unfortunately I was only able to test it briefly with my plain vanilla Sandisk 1GB. It came up with only a "5" score! Needless to say, when I tried the auto SD speed detect, it was not rated fast enough. We have an UltraII in the house, but its in my kid's DS and he was very budy with his DS tonight. I'll try to give it a shot tomorrow.
My problem with the SCDS1 at this point is that, like every other Slot1 AFAIK besides the DS-X (which I am NOT tempted to buy), it falls short of the last-gen Slot2 cards. At least, so far that seems to be the case. My SCLite takes that same plain old Sandisk 1GB and plays anything and everything I'd ever care to play at 99.999% real speed, without all the hassles. I just hope SCteam keeps supporting it, just like I hope they figure out how to squeeze some proper performance out of the SCDS1.
One more thing ... this is being called a firmware update, but isn't the real firmware unaffected by this update? The moonshell based GUI is the OS, but surely there's a "BIOS" on the card itself ... hopefully there's a procedure in place for flashing it, cuz I suspect that's where the real improvements are hiding.