I have a pair, and find that they are slightly warmer than regular jeans. I also find that they are more comfortable when worn with long boxers or such underneath. I guess the Kevlar chafes my tender skin, LOL! I might also add, that in my case, they run smaller than my regular jeans. I wear 38s in my Dickies painter jeans, but wear 40s in the Draggin jeans. YMMV. I really like the external pockets - great for cell phone, glasses, etc.
As far as protection, they are far better than regular jeans, but perhaps not quite as good as a good ballistic nylon, armored overpant. Over course, leathers are the pinnacle of protection.