Right up front I'll say I am no expert on rap, but I have used the KSM32 and the SM7b a fair amount, and personally I can't imagine why anyone would want all the high frequency in the KSM 32 on a rap vocal. The SM7b on the other hand sounds like rap sometimes even on non-rap vocals, so it would seem to be a better fit. But, just my opinion, YMMV.
Ed Billeaud - Snowflake Studio
There is no justification for the exploitation of weaker beings. We cannot advance as a species until we respect the rights of other species. One Earth, all earthlings. http://www.soundclick.com/edbilleaud