Quoted from Guinnesstime:
Yeah but the reliability of the premium mechs suck. They're just cheaply engineered and most need to spend hours getting them right.
I have literally made zero mech adjustments and only two part replacements ON A ROUTE MACHINE.
I think the early prem/le were worse, there were a lot of horror stories. This Premium was from after the initial run or late in the initial run and has been fantastic aside from the newton balls needing replacement (they popped off their posts).
There IS still the issue of playfield bunching that affected some unknown portion of Iron Maiden machines, Prem AND Pro, so that's also a consideration.