There's a nice synergy/karma to climbing and weight for me. I started at 225, 5'9", am down to 195. On the way to 170 I hope, and beyond?
Anyway, naturally strong legs to begin with. But the legs got stronger climbing with 225lb, so that when the weight came off, it was compounded by having trained harder because of the extra weight. If I hadn't weighed that much to begin with, I don't know if I'd developed that same strength.
I noticed this when I took some winter cycling classes (pretty tough ones). On a stationary bike, without actually carrying the weight, I was able to push hard compared with the class.
On the road, I'm still not the fastest up hills by any means. But the weight has been a blessing in helping me gain strength to carry it...even more noticeable as the weight comes off. Great synergy. There's a gift in everything.