As an overall piece for road bikes, I prefer older styles with horizontal top tubes and thin / regular tubes. However, for some of the details, the way carbon can be used around head tubes and the BB looks glorious.
For off-road bikes, I'm see much of benefit in both old-school steel with no suspension and in modern frame shapes and resolutions to the problems trying to get suspension on a bike.
For off-road bikes, I'm see much of benefit in both old-school steel with no suspension and in modern frame shapes and resolutions to the problems trying to get suspension on a bike.