I stopped using Ortliebs when I started traveling light. They're fantastic bags, but heavy. A set of Ortlieb front bags is just shy of 4 pounds, the rack is probably another pound. That's five pounds. Rear bags can be another 4-5 pounds. If you're trying to get under 25 pounds, 5-10 pounds worth of bags is significant.

If you're worried about weight distribution, hang a dry bag off the handlebars to move some weight forward.