Also a big advantage is the averal weigth of all Japanese guys. They're all smaller and lighter people than the average European persons.
And the sprinter posted above. Isn't everything fabricated out of aluminium? Pretty cool... And light weight also. But I don't see the benefits of the use of an AC cilinder over an LC. Regulations can be the only factor. The thermic balance in a LC cilinder is so mutch bether. And you don't have to worry about cooling in 50 meter's... Just a bit water in the cilinder and the small radiator will do. Or try to get a sort of "thermocifon" stream of the fluid.