I'd just like to say I'm glad xubuntu devs are considering xmir. I briefly tested the ISO on my laptop (system 76 lemu4 with intel hd4000 graphics), and I'd like to discuss the one very important advantage I noticed to this configuration as opposed to pure X. When running Xubuntu on xmir, I got NO VIDEO TEARING!. This had always been my biggest issue with XFCE/XFWM, the ugly video tearing when scrolling in firefox, watching videos, moving windows etc... I had always had to resort to using a 3rd party opengl compositor (and I'd rather not, I prefer to use the native WM). the best alternative I had found was using compton which allowed for tear-free opengl compositing without replacing XFWM, but it had some weirdness with how it drew shadows. In my testing of the ISO on intel HD4000 there was absolutely no tearing, and smooth scrolling in firefox was butter-smooth. I watched a fullscreen html5 video and again, no tearing! For this reason alone I hope xubuntu strongly considers using this! IMO video tearing is not acceptably on a modern desktop!