I have a Diabolic with approx 20 flights on it. Great fun fly amazing build quality like all the top model stuff. I would say that the Diabolic is a pure 3d type plane. Amazing 3D potentiol but dont expect it to fly like a pattern plane. I found mine wanted to tuck in anything above slow forward flight. Got used to it and started flying it on the stall where the tail comes into its own. Amazing vertical dives with negative parachute at the bottom. Looks supereb as it is fully stalled with the nose pointing 20 deg up but model coming vertically down.
I have a Irvine 53 in mine, just enough power to climb out of a prop hang I would suggest more power.
I only had one problem so far with the tail linkage causing a crash and that was due to the metal servo arm falling off the 8411 on the elvator control,
Apart from that this is a great fun fly with a bit of difference that makes it stand out