The worst thing I flew in the RAF was the Jetstream which has been mentioned many times. The engine was good, once you got it started. But only good for pilots - engineers hated it. It was the handling that was bad. As it had several handling features unique to the type, it was particularly unsuited as a training aircraft, unless you had adopted 'if you can fly this, you can fly anything" philosophy. The C130 was the major customer for the METS output (5 out of 8 on my course) and you could see the wisdom in using a fixed turbine, But the Aztazou? It was unique with it's blade angle reference outside the Beta range - and it's heritage as a helicopter engine quite apparent.
But the course was also poor, being heavily C130-centric and a lot of time was wasted pilots going onto other types. I went to the Victor and had to do a 15 hour refresher before the course re-learning how to fly with techniques never to be used again. The only thing that was similar was the shape of the control column, as both were designed by Handley Page!