Yes well that should be fairly obvious, but two solid balls of the same material(density) but of different size(mass/volume) will fall at the same speed/velocity.
If dropped at the same time from the same height/altitude will hit the ground at the same time.
This according to Galileo.
But other scientists say it's not true according to their formulas but don't bother to test or demonstrate their hypotheses in reality. (If you know of any such demonstrations(not formulas)please give me a link.

I have seen it successfully demonstrated on video somewhere in the UK.(can' find it now)

It's amazing that in this day and age that the answer to such a simple question could still be in any way controversial. Just like the controversy as to how an aeroplane wing gives lift.

Yes we all know about the vacuum dropping thing. They never stop going on about it.