Ubuntu 16.10 vs. 17.04 Radeon Graphics Performance
The R9 270X really benefited from Ubuntu 17.04 while the higher-end R9 Fury and RX 480 didn't see much benefit for the newer Mesa and kernel.
The CS:GO results should be more interesting later this year when the Source 2 Engine implementation rolls out.
Dota 2 with OpenGL also saw a nice bump on the R9 270X with Ubuntu 17.04.