Tom, this is all true. Any one isolation scheme doesn't answer all the problems, so you have to go by what sounds best for you.
Actually, the best isolation for a cdp I ever tried was hanging my player with fishline from the ceiling. I would like to return to that again, the problem is I have a cathedral ceiling now, makes proper mounting a much more complicated affair. Still, even this does not totally isolate from air, ceiling or internal vibration.