I wore chaps when falling timber. In the mornings when the brush was wet they would help keep me dry. When servicing the saw they offered a nice cushion when kneeling down, and whenever the oil cap fell out of the saw they kept me from getting covered in chain lube. Icky.
The straps on conventional chaps can tangle in the brush at inopportune times. Bummer and scary when you're exiting from a falling tree. They are easy to take off if it gets too hot.
No problem getting tangled in the brush with the pants, but they are not so easy to take off when it's hot. Plus the pants would slide internally when I was trying to crawl over any log larger than I could step over. An inconvenience at times.
The safety value of chaps is undeniable. Now, I'm not sure, but I think they are required by Cal-Osha for woods workers, who run saws, to wear them. Please, anybody, correct me if I wrong on that.
I can't really say that chaps have ever saved my bacon, but if I wasn't wearing them then my fate would have been altered. so it's hard to say.
I'm retired now, so I can say this without jinxing myself, "42 years of running saw in the woods and I never cut myself." But if the truth be known: through my career I narrowly escaped serious injury from the chainsaw on several occasions. I thank my lucky stars. Just lucky I guess.