FWIW, I have been running Xubuntu on a not very beefy Dell Zino box for about a year now.
When I had it running Ubuntu or Debian with the full gnome desktop it struggled to cope with netbeans plus the usual stuff all running at once.
Under Xubuntu it is quite happy running netbeans plus Coherence as well as the usual desktop stuff.
Cheers,
Ewan