Doesn't really hitch all that often for me either. There are just rare, random instances where I notice animations with dropped frames. Not all that a big deal and I'm not sure if reducing transparency would actually help.
The only really reliably reproduceable thing is activating the quick action menus in landscape mode on the 6s Plus. Not sure what's up with that and why that's still a thing in iOS 9.3.
Agree with you. sure it hiccups sometimes but overall its pretty smooth.