Diana-2 - master-piece or flop?

I have read very good critics about Diana-2
but as well very bad news about it.

The good news are from the people who seem to have flown the first two
Prototypes. The bad rumors I heard about number-3 of Diana-2.
Obviously the main difference is, that the wing position was shifted some
centimeters to the front. The glider appeared in Australia last November,
flew with experimental permit, but never got the airworthiness approval from
the Australian Airworthiness Authorities.

The gossip mentions problems like:
- airbrake movements being asynchronous
- flap handle unlocking in flight and shifting to full positive
- too high flap handling forces (more than JAR22 limits)
- weak aileron control at take off until tail wheel is off the ground
- glider is stalling while thermaling over inner wing at speeds CLmax with
- aileron control not good enough to keep bank when circling 30deg
- glider was in general instable to fly in yaw and pitch

Did anyone fly serial planes of Diana-2 with manufacturing numbers 3?