Is there more sound out of the side speakers in 7.1 and less or little out of the rears?

My rear speakers will be close to my head and I am thinking about going with QS4s there rather than the QS8s that I planned on.

I would stick to QS8s on the side because they are farther away and there is more side sound right?

Does this make sense or am I not going to be happy unless I go with QS8s all around?

I have the M22 and VP150 up front and plenty of bass to handle the low end.