I am sure if you took two identical kicks, tuned them the same with the same heads and left them empty. Then have toms on one and not on the other you would heard a difference. I have alway felt that the weight of the toms and hardware would put stress on the shell.
i think that its not so much virgin or ruined but instead if the kick has toms or not. i think that if the drum does have toms mounted off of it, the extra weight kills resonance. my bass has a tom mount but i dont have anything mounted and you can hear a difference. before, the bass had a muted sound, but now it sings alot more and has nothing to deaden the resonance. its actually pretty noticeable.
plus i like how it looks.