If you haven't shelled out the money for the higher $$$ hunting pants take a look at the zip-off leg fishing pants offer by several makers. They are all about the same. They are very light, reasonably tough, and very comfy; I have probably 6-7 seasons in 2 pairs and they are still going strong. Since they are so light you can pack in an extra pair. I wear one hiking in/around camp and then use the other pair when hunting. It nice to have a cleaner pair after one gets really soiled or blood on it. You can add layers of wool long johns as needed if it get colder much easier than the tighter fitting pants.
Just a thought.
