Considering the same reasons as in this previous question on Cinnamon, it would be interesting to know where does Mate DE stands in this context - between Unity and KDE on the one hand, and Xfce and LXDE on the other.
So, to clearify:
On a laptop with 1GB of RAM there's a sensible yet tolerable difference between LXDE and Xfce: between these and Gnome and especially KDE and Unity, the difference is decisive. I use in parallel Xfce and LXDE, and wander whether there's another usable DE for me on this computer: all are "usable" of course, but compared to LXDE/Xfce not all are acceptable.
This questions stands being closed: I guess you should close the other one too then.
As reediting was suggested in comment: to put it as non-subjectively as I can: is Mate heavier on resources than Xfce? Is it lighter than KDE?