LT, I agree with most of the opinons for the most part, but I have to agree with TXjourneyman there isn't much that'll keep you "cool" in those conditions. I wore my BDU and pants on opening day in Oklahoma this year, it was 96 degrees and yes it was hot, but it was far better than lots of cotton items I've worn in the same temps. I wore a proper (extremely breathable) summer base layer and it was about as comfortable as I've been in those temps.

As for how it does in cold weather, it's extremely versatile. It's so adjustable that it can fit properly with nothing or everything on underneath it. In the picture I'll post below, I had 2 base layers, a fleece, and my carharts on under it. I can still shoot my bow with all that stuff on becuse I can sinch it down tight and pulls all the excess underlayer material out of the way. You can also get some insulated however you like as well.

The 3D suit should be out soon and as most 3D's it should be excellent in extremely warm temps.