Hey Brian, have you thought about the Formosa ? I really think this is one of GWS's best flying aileron planes. So does Mr. Lin. It has very nice manners, if built light with correct C.G. and best of all it's cheap and easy to repair.
If you don't mind building, then I really think Mountain Models, Dandy and Switchback are a great step up from primary trainers, with good flying traits+ easy to build. Unfortunately, I have no experience with the "Split 280" so I can't comment on that, but from the looks of it, it seems like a decent airframe.