They serve their purpose, but I wish they were better
I bought these for cold weather running in Minnesota. They are not warm enough to wear on their own, but a base layer of leggings they're OK. I bought a large because I wear leggings underneath but they're still too big (I didn't bother to return because it's wearable for me). I have a pair of this exact kind from about eight years ago that are made from a warmer material and can be worn on their own, so something definitely changed with the material. I'm 5'5" 145 lbs, and a medium would have worked better for me. Despite keeping them and running in them, I'm still searching for a decent pair of winter running pants.