This looks like an interesting page to add to the yet another site on the list to ready (dashes added to this last sentences).
I am member of Post Status and I do enjoy being in the know of what’s happening with WordPress, so this should be another good reference.
I have come to the point of really wondering what per-processor for CSS would be best to use. Since I’ve been following CSS-Tricks for a few years now, I think I’ll trust the following statement about Sass vs. LESS:
Really short answer: Sass
Slightly longer answer: Sass is better on a whole bunch of different fronts, but if you are already happy in LESS, that’s cool, at least you are doing yourself a favor by preprocessing.