Don't you mean Trisquel 7? Unless we're talking about the next release? :-P
Anyways, I voted for XFCE. When I setup my system with Trisquel, I basically use it like Debian and went with a minimal net install. Then after that was done, I installed XFCE, my programs I like, and compiled a newer version of Linux-libre.
It works well for me. It's not exactly what one would consider the easiest out of the box experience, but it suits me and is tailored to my needs/likes.
I did consider using a tilable window manager such as i3, but for the programs I use as well as my workflow, it just made more sense to use XFCE. It's light, and stays out of my way.
I think the default Trisquel environment is good for people who want a no frills desktop that works well out of the box. (Don't get me wrong, I think it's well done.) Me personally, I don't like branding much; nor am I a fan of Gnome fallback, so I opt for something else.
My two cents. ;-)
