You will save a lot of hard drive space at your destination when you rsync a backup using "--delete." Especially when there's a temp file directory included in what you're backing up. Say... 40 gigs?
[and the trumpet goes "wammp wamp"]
As a side note, make sure the rsync --delete is going in the proper direction. I have never made this mistake, but I can only imagine how upsetting it would erase the original you thought you were backing up.