i used to use Melodyne when i was working with a couple of MC's. at that time there wasn't really anything that was as powerful as Melodyne...well maybe Antares but Melodyne was killin' it.
Motu's DP4.6 now has what i needed from Melodyne but its built into the DAW. if your a mac user its worth looking into:
DP4.6 linker...whatever get the job done
peace
a