Scott,
I think the difference is the difference between the two designs, as you said. The Extra is just such a neutral flying plane. Lots of folks say Extras exhibit a bit of coupling in knife edge. Mine has so much power it takes hardly any rudder to knife forever, so I don't see any coupling. I have full 3D throws on my CAP and the CG is as per plans. My Extra, however, doesn't have those cool, long H9 horns like my cap so its just set up a bit tamer. Also, its a bit nose heavy. I think both planes are so good they could be made to do anything you want. I feel the chars. of my two plans were self determined. Still, the CAP's my baby. Ijust love the way it looks in a hover!