I've been running a Graupner X-8N for just over 2 years now and it's working really well for me, never a single glitch, nice and smooth. Only mod I had to do was add a back stop for the throttle trigger, I damaged the original trigger and it was replaced free of charge under their 2 year warranty and the problem hasn't come back with my new back stop mod. The newer X-8E system comes with a backstop and slough of other nice features, I actually have plans to upgrade to the X-8E in the not too distant future.

Here's the mod I made to the X-8N by tapping a 3x20mm screw in place: