I've looked over this set up a few times over the past few months and keep coming back to what Dick said. You are loosing servo power with this set up and increasing the slop at neutral. The power issue would have to be overcome with additional servos, thus taking away any cost benefit from foregoing the linkage in a standard set up. Slop at neutral is a huge issue for precision flying and even a larger one for flutter concerns.

That being said I applaud the thinking "outside the box". What you might want to look into is having a manufacturer make a special servo that only has 45 degree throws (each direction) BUT have new gears and/or motors to double the torque at expense of servo speed. Think about it this way as in reference to Dicks numbers above. A current servo (in a standard linkage set-up) needs to be .12 seconds as it MUST rotate fast because it must travel twice as far of a distance to move the surface the appropriate deflection at a desired speed (i.e. 120 servo travel for 60 degrees of surface travel....the output shaft travels .12 secs but the actual surface only travels at .24 sec). If you can have a manufacturer build a servo that has additional step down gears (which would result in a slower servo......all else being equal) you could in essence double the torque at the expense of halving the output shaft speed (which would still render the same control surface in this direct drive system).

.........Mark