The new tail design appears to increase the area of both the rudder and the elevators. It also appears that they dropped the need for the tail braces... If mine wasn't built I would contact the importer, Airborne Models, and see if I could get just the new elevators. They shouldn't cost too much and have the extra control surface might be good.

As for whether or not the new control surfaces make any difference -- I don't know. There are lots of 3D models, CAPs and Extras, that have similar ratio of fixed to movable tails feathers that the version 1 of the FW3D has. It might just be marketing thing too. If you look at other "3D" models in the mags they all have the extra area on the tips (can't remember the correct term) of the controls, and have a very small fin in relation to the rudder... I think getting the CG right will have more effect on the 3D capability since I'm sure the recommended CG is too far forward...