The Hobbico NexSTAR does not "deviate" from successful design parameters for an R/C trainer aircraft.

The person who designed the Hobbico NexSTAR is a world-class flyer who has moved into model design. The airplane was designed, tested, re-designed, tested, and so on until the objectives of the design were achieved. The airplane was then tested with a wide variety of non-flyers, novice flyers, experienced flyers, and so on before it was put into production. The lead designer had many years of model aircraft design experience before he was chosen to lead the NexSTAR design project. The NexSTAR was in development for a few years before it went into production for general release.

Again, if the model doesn't fly the way you want it to, you may not have it set up correctly, may be trying to fly it outside of its intended flight parameters, or there may be an actual difficulty with the construction of your particular model. It's not in the design of the aircraft.