I suspect that when you really notice has a lot to do with both your starting weight and the sort of activities you do.Huh, that's interesting. For me, I only really noticed much difference when I got over 200 lbs and I'm only 5'2.
I guess it depends on build and stuff too though. Although this sounds like an excuse, I do literally have really wide bones and such that makes me carry weight much easier, from what I can tell. I think most of my issues come from me being sedentary more than my weight per se as well. I'm trying to work on that but chronic illnesses make it hard.