the voodoo5 was designed more for the agp interface and around hardware t&l software- directx 7 iirc. on a pci bus with non t&l software the 5 would only be a bit faster due to faster core and mem. the additional features would be unused.
so t&l, multitexture, pixel pipe optimizing (slightly different on the 5), and antialiasing (i think) would all go unused.