We've had this discussion before ... I think the consensus is that it depends on the climbs.
Small hills are like intervals, long ones are like a tempo workout. Hypothetically you could climb 10,000 feet in 100 miles on one long 2% grade, and barely feel it in your legs. Or, you could climb the same 10,000 feet the way we do in southern Ohio, Indiana and Illinois ... by climbing the same 300 feet over and over again on grades of 12-25%. That, you will feel.
6400 feet in 127 miles is not a lot of climbing for southern Ohio. But if you're not used to it, anything is a lot.
Speed comes from what you put behind you. - Judi Ketteler