I've never used 2mil coro, only 4 mil and have built LOTS of different spads. My step son flys the v-tail spad very successfully (1st place this season) and I fly a 4' wing, 28'' fuse with healthy tail feathers. Because of the 4mil we both use os46fx motors and they scream. The most important thing is to start building and never quit. Every time you build you learn, it's a blast.