I paxed on them numerous times LTN~IOM and found them to be fine and never a tech canx, IIRC. However, I do recall reading in one of these forums the opinion that the wing was misplaced and that subsequently, balance for departure was keen.
Also that it provided a real flying experience for the drivers - this was seen as a positive, albeit a bit of a sideswipe, as they meant that you had to keep on top of it.
I sit to be corrected.