On tillers the main advantage that has not been mentioned yet applies to all low profile tillers of any material. (The only low profile ones I know of are made of Carbon.) The low profile helps the traveller blocks sit farther outboard as the rise created in the middle is less so there is less tendency for the blocks to creep back to the centre line in lighter breeze. It is significant when comparing a low profile tiller with a standard aluminium tiller after a tack. Yes Carbon tiller extensions do not like to be "bent" over the gunwhale but then neither does aluminum. Carbon does not feel as cold as aluminum. This makes a huge difference up here in the colder climes on hand fatigue. (gloves don't help when it is that cold) Just my thoughts.