Apart from the gasket farce, In what way is it not a strong engine? It is a 20 year old Mazda engine the same as the 2.0 ST engine. Improved and strengthened for turbo charging. Used in 100000 of cars ultra reliably, just won yet another award last year. Ford engineers claim its maximum reliable design power is 375 hp, over double its original power. If you go above that you are pushing it. It is already near its limit and at it with mp275! Same with any engine including the volvo 2.5 with its notorious liner issues. I guess this is why manufacturers put a lot of r&d into lifting the power. Nearly always with serious engine mods even for moderate increases.
2.3 is not a strong engine, but what a fabulous car.
So I totally disagree, it is an extremely reliable engine. Not heard of any failings whatsoever in mk4 st or Mustang. And not in standard Mk 3 RSs either. Only modified cars.