The engine on B3 is new. What Vstol is referring to is merely an uprated version of the same engine. While engine core life will drop down by half, it's still 2.5 times more than the M88-4E, 2000 hours vs 800 hours. The current one gives 4000 hours. At the very least, there was no problem with the engine option from SH.
Avionics too, it was hit or miss, some things were better, some were worse, some did not even exist.
The issue was the airframe, it's very old, too big, too heavy, reduced performance, tougher maintenance and so on.
Basically excellent avionics and engine, sh!tty airframe. The only good thing about it was its higher service life.