From my personal experiences with my own fursuit skin tight feels about the same amount of material, can get just as hot when you aren't moving but there are no air pockets really to capture and store heat in so that can help not be as hot and mobility definitely is sacrficed with skin tight to avoid popping seams nonstop.

If you go with an actual spandex bodysuit, they definitely do require less material, don't get nearly as hot, and definitely increase your mobility; however, they only look good if you have an OK physique, and a lot of people are uncomfortable with spandex bodysuits even if you do have a good physique.

Personally, I like them a lot. Here's a cheetah: http://www.furaffinity.net/view/4460667/

Fire Leo: http://www.furaffinity.net/view/10473891/

A cougar: http://www.furaffinity.net/view/4493883/

I've yet to see someone do a really good spandex interpretation of a wolf or a fox or some slinky critter like a genet or a cacomistle.

http://www.furaffinity.net/full/14985076/ this also what I have seen.

Yeah, that one would probably get pretty toasty after a while. Though you'd probably have a slightly better range of movement than a traditional "mascot" style suit.

There used to be a company that made a four-way stretch fur fabric, by the way. Don't know if they still exist. They were called National Fiber Technologies (NFT).