Depending on the distro, MATE has a lot more stability problems. It also has more UI inconsistency problems (again depending on distro). Since youre moving from windows Ill point out that MATE is a fork of a desktop environment which used to be very popular, Gnome 2. Gnome developers started Gnome 3, which lead many to switch to XFCE, KDE, and for a fork called MATE to be made. While MATE itself is fine as its basically the old Gnome 2 with improvements, I wouldnt touch MATE on Arch. Maybe Ive been following the MATE thread on the Arch forums too long, but it seems like guys there have tons of problems with it. Maybe im wrong here? It seems like random guys having to come in and pull this and that, struggling to get X or Y to build, finally getting a decent version, and then uploading. I do see MATE in the community repos so perhaps all those issues have been sorted? Cinnamon is usually very stable, and a nice mix between the simplicity of something like XFCE versus the feature heaven of KDE. KDE is the most UI consistent interface on Linux and has a mind-boggling array of features, but it has bugs here and there. XFCE is a fantastic DE- it can look very good, its pretty light, its got a lot of features but isnt bloated, and its very stable. I mention XFCE because I havent seen you mention Xubuntu- probably the best buntu distro available. Might want to try it, but please do give it a chance by dressing it up a little- its pretty plain at first. MATE and XFCE are similar in a lot of ways, though not all. I could also suggest window managers, but based on what your testers like none of them would prolly be a preference. I personally use Openbox with xfce's panel, file manager, terminal, and system settings along with compton for compositing/tear-free/etc.