Do you actually "climb" upwind with assymetric boards?

I was told that there would be lots of parasite drag when foils are "climbing" the boat upwind.

I was also told that with asymetric boards upwind the boat actually heads lower while sailing the same course over the water of a symetric board boat. The advantage of heading lower is that the hull would not be generating lift, only the boards - their lift is generated with aproximately zero angle of attack, so the hull is aligned with the flow.

Since the boards are more efficient (long span, etc.) generating lift than the hull, the drag increases slowlyer with speed and the boat sails faster with the same power.

Maybe you are climbing due to other features, like the wingsail? Please let us know - and thanks very much for the great photos and info.