the vampire a600 will blow away any known accel for a600. I had the vampire v1 it was awesome.
Of course the Vampire is much faster, but the Furia is really cheap (the Vampire is not expensive, too and has a really excellent price/performance ratio). I myself am undecided whether I will pimp my A600 with a Furia or a Vampire. Both options are nice. For the occasional retro fix the Furia probably does the job just fine (for little money).