I would completely redesign the overhead panel and incorporate the lower pedestal onto the overhead, like most transport cat. A/C, and install side windows that can slide back and get rid of that ridiculous 'plug' of an emergency exit on top that is nothing more than a death trap when you actually need it compared to the size of some of our CA and crew....Other than that put a true FADEC and the 700 engines on the 200 and install a RECIRC fan and i would fly this plane forever, I just hope that I don't have to !