We've recently started using CrashPlan but not to their cloud. We
brought a computer into the office, backed everything up to it, then
took it offsite. Only a few days to get multiple computers seeded
that way. With that we only pay CrashPlan $10 a month for up to 10
computers, though we pay for our hard drive space.
Did you see these tips?
http://support.crashplan.com/doku.php/recipe/speeding_up_your_backup
The defaults for CrashPlan allow for only a little CPU and a little
use of bandwidth. Once you open up the throttle it does a lot better.