Performance Anxiety

...how big is your prop?

The only minor concern I have regarding the Canadair 415 is whether the props are sufficiently large; I traded in the 8x3.8 slow-fly props for three-bladed 7x4.5's following the methodology of dropping one size going from two blades to three. However, in this case, the original prop is a slow-fly paddle version, so I'm thinking that going for a regular eight-inch three-blade would have been a better equivalency. 

Anyway, I might do a power test on a scale just to get a rough idea of how much thrust to expect; the 210W bell motors are rated at a max 880g thrust which, pushing the lightweight Canadair 415, would probably give it unlimited vertical performance...