You have to be the first person I've heard say they prefer the Obsidian's in thick brush. I get where you are coming from with the tightness of the material weave and feeling thorns, however, the Obsidian's just aren't meant for brush busting. That's not what they are designed for and the merino material doesn't hold up well to it. They are a quiet pant, they breath really well, they don't hold stink, they probably have a slightly wider temperature swing where they would still be comfortable, but their weakness is in wet conditions or thick brush. The Corrugates, being made from Nylon, are much more durable, dry quicker and are still quite breathable. Different purpose to each pant. I own the Kanab 2.0 (predecessor to the Obsidian) as well as the Corrugates. I like both pants for different purposes but find myself wearing the Corrugates more frequently for the conditions I hunt. I'd say the Obsidian's would probably be slightly cooler in hot temps, but they won't be nearly as durable in thick thorns.