Everything matters, so you do not need to compare importance. I know what he said, but I will post it anyway just so I am one post closer to legendary viruoso. B)

Here:

The second important point is this: avoid resting the violin on the shoulder or, vice versa, shoving the shoulder underneath the violin. The placing of a cushion beneath the back of the instrument, in order to lend a more secure support to the chin grip, should also be avoided. These are bad habits, which one from the very start should carefully avoid, since they not only spoil the violinists pose in general, but-and this is extremely important-they make the player lose AT LEAST a third of the whole body of tone which his violin-be it a fine or an indifferent instrument, a powerful or a weak one-is capable of producing.

There. Straight from the mouth (or pen) or Leopold Auer. Please take his word for it.

__________________
It is our imperfections that make us who we are.