I agree, you shouldn't see a lot of noise in the T1i....especially in the lower ISO ranges. Its a great camera.
If you decide on the 5dII, you will love it. Its a fantastic body. I don't know why some folks have issues with the autofocus. Its not the best, but its very accurate. The points are pretty clustered around the center which isn't real great, but I can easily work with it. Shooting sports with it is not a problem. Sometimes I wonder how sports images were ever captured years ago......if you listen to everything you see on the internet. LOL My 5DII is obviously not what I reach for first to shoot fast paced stuff, but I often couple it with my 1DIV to shoot sporting events and it works just fine.