Have used one, yes but I don't recommend it if you're going to play Nightlong, Earth 2140 or Wipeout 2097 because the games will be shown in something that looks like 32 colours...it has to do with something called "big endian issue"
The Voodoo driver from Elbox is written for the Voodoo 3 card but it compatible with the Voodoo 5500
The Voodoo 5500 will only produce more heat in your case, the only benefit would be that you'll have 16mb more RTG memory with a Voodoo 5500 compared to the Voodoo 3
