Check to be sure about the performance. I don't think it is faster. The climb might be better, but not by much. Also, make sure that the roll rate is dropped some as well, seeing as there aren't spring-tab ailerons on the -3 like there are on the -5. No rockets as well on the -3.
I want it for sure, but please, before you bring the -3 in, update the 3D model of the -5. It looks its age.