You will find alot of positive comments on the ultra sport 40 and 60.. I have never flown them, but I have seen them fly...nice planes. Years ago I built one for a guy and he always liked that plane as much as any other he had owned. From what I have seen they probably fly cleaner ,smoother than the 4* which is very floaty and stable. Both great to build and fly, both also lend themselves to kit bashing or customizing ...