I'm thinking of doing the same. The H75s are bright speakers... Do you notice an obnoxious amount of high end? V30s are bright speakers obviously as well, at least they are very pronounced in upper mids. Do the H75s seems to "smooth" out the cab or do they just fill in the frequencies that are lacking in the V30s (higher treble frequencies)?
I keep buying and selling V30s. It's always been love/hate and I keep wanting to incorporate them in my setup in some kind of mix but I always grow tired of the grating upper mid spike and grainy tone. I have some nice Weber Legacies and Gray Wolves and some G12-T75s also. Wonder if one of those sets would match up better?