> These days many of them are moving to 'xubuntu' (mainly avoiding the unity+gnome3 mess).

Wouldn't Debian work a bit better and come with a better long-term stability policy? It seems strange to rely on the *buntus unless you're specifically relying either on proprietary software that's Ubuntu-targeted, or commercial support from Canonical. (But there are some spaces, e.g. GPGPU compute, where either of these might be relevant and Debian still has quite a bit of work to do before it can be relevant.)