For most of us, climbing speed is the biggest factor in our overall time. I'm losing weight, but not too fast, because I like getting faster. If I got down to my target weight I'm pretty sure my performance gains would plateau and I'd have to start working to get better. Where's the fun in that? I have lost enough weight that climbing is noticeably easier though. Went up a hill that usually kicks my rear last weekend. It still wasn't fast, but at least I didn't curse the day I was born the whole way up it.