I plan on trying a TT 91 4C to start out with. It's about the same weight as an OS 91FX, and supposedly will turn a 15x6 prop in excess of 9500 rpm. How'd the plane balance with the FX and standard servos? Will using minis on the elevator halves make the plane nose heavy? You guys think that this will be enough to hover and pull out vertically? I've also got a YS 91FZ, but it's slated for another project...