The problem.....let's say the problemsss
Very cramped...361 pax, no legroom, tiny galleys so no space to store stuff, only 6 toilets with tiny tanks so they are always full/blocked and the smell...
Reliability....umm. But yes they are Monarch most profitable aircrafts.
Pb: the late arrival of the dream on liners which were meant to replace the A300s. So Monarch have to keep the fat piggies going. They are just a nightmare to work on.