I'm That Guy, don't be me
Better is all in the eye of the beholder, so that is up to you.which one is a better choice 4500 or 3700?
We don't know all the specs of the 3700 yet to make a full comparison, but it will likely be the 3600 plus HDMI 2.1 (which is what this thread is all about) being the main addition.
Read dfa973's full comparison and make your own choice:
Gain/Loss comparison of Denon AVR-X3600H vs X4500H
Plus the 3700 will likely cost more at release than the 4500 does now.