Not an exact answer to your question, but since the devices are almost the same:
My wife has the P7Pro and I own a 6.
I decided for the 6 instead of the Pro due to the difference in size, but you know what the 6 (or 7) is already a (too) big phone. To me it doesn't matter if I carry my 6 or my wife's 7 Pro.
The additional zoom on the Pro makes a world of difference to me, so my next phone I would put camera above size if the size difference is so small that there is a hardly a real world difference for me.