David:
My friend has the 40 version and the goodies inside was a tight fit so they made the fuse roomier. The canopy and cowl are just for aesthetics. From the way my friends and mine flew they didn't need to change anything else as far as aerodynamics goes. Im going to buy the 40 version when it comes out. I don't think you would be disapointed.
Their website is at [email protected] In case you want to keep an eye on when it comes out.