RadeonSI Benchmarks On Budgie, GNOME Shell, KDE Plasma 5, LXDE, MATE, Unity, Xfce
With BioShock Infinite on Steam there was no measurable difference between the eight tested desktops on Ubuntu 16.10 when using the R9 Fury on the RadeonSI open-source GPU driver stack.
Before reading too much into the GNOME Shell and Budgie results, don't be too concerned by the reported number. GNOME Shell / Mutter seems to have an issue with Source Engine games when triggered via the Phoronix Test Suite that they lose focus and seem to have thing the window is not responding. That bug is why the reported frame-rate is much lower. If running the games normally, the frame-rate should be in line with the other desktops not posing this problem. Aside from that caveat, the other desktops were all roughly performing the same with this high-end AMD graphics card.
The Metro Last Light Redux performance also performed basically the same on the eight packaged desktops found on Ubuntu 16.10.