simply put, wii64 ought to be much better than other homebrew emulators. Have in mind it was not hastily made by a few SNES fanbwoys with acne but derived from mupen64 which is a robust cross-platform plugin-based emulator.
mupen64+ home page
This said, I am not going to argue whether it's superior to the VC or not. Heck, there shouldn't be anything wrong in using both if you're serious about emulating the N64 !