For myself with drums - I just believe the audience is there to watch me make music - with whatever tools it takes  to do that. And set-up the way I need them set-up to best play the music. So I have no problem playing mis-matched kits if that's what serves the music best. In fact, the fact that the floor tom or one bass drum or whatever is a different color/type/brand than the rest of the kit just makes it more fascinating to the audience - "Hmm, what's deal with that odd colored drum? Oh wow, it really DOES sound different than the other drums".