I had a Voodoo5500 in my A1200 for a week then went back to using my old Voodoo3000. The Voodoo5500 benched slower in P96speed for some reason.
You can overclock the Voodoo in Amigas via the voodoo monitor tooltypes. Add OVERCLOCK=YES and MEMORYCLOCK=xxx (where xxx is the Mhz you want)