I have the full wrap. I figure that if I need them, I NEED them and don't want to wish I had even one more layer of protection if something goes wrong. In hot weather I wear shorts too. I'd rather be sweating and have to change pants once a day or even twice a day vs. having to throw the pants out because they got cut. I run a CS-340 Echo with 14" bar to a Dolmar 7900 with a 32" bar.
A friend has cut both Stihl protective pants and chaps. Both saved his butt, but both times it was just a graze. The pants are HOT he says. Both times he didn't even know he hit his leg, the saw just stopped and he didn't know why. I told him that he was done cutting for the day both times. I was there with him, but not next to him.