Mate 9 proved to be the best phone i ever had, easily outdo the S7E, which was good phone nonetheless.
S8 will have awful battery life and DVFS is still there, to date, the Mate 9 is the only phone i don't need to root in order to play Tekken 6 in 60fps via ppsspp, it doesn't throttle on bit, where the S7E couldn't play it smooth at all...
Note 8 might swing me a bit, but honestly all those flagships are overpriced if, I'm waiting for a phone with high-quality DAC, huge battery, 6.0+screen, IP68, wireless charging and some other cool features, bascially Mate 10 maybe