I've play the OLP Petrucci quite a bit, and I've played the MM1 before.
The Petrucci came new, played perfect out of the factory. The MM1 had mile high action and sharp fret ends. My takeaway was that the QC varies a lot either from guitar to guitar or just model to model. Since you're getting it used, hopefully the previous owner already sorted this out. Either way, I'd make sure to keep some extra time/cash put aside for some basic TLC (fret de-burring and polishing, filing down 'fret sprout', truss adjust, etc.)
The Petrucci came new, played perfect out of the factory. The MM1 had mile high action and sharp fret ends. My takeaway was that the QC varies a lot either from guitar to guitar or just model to model. Since you're getting it used, hopefully the previous owner already sorted this out. Either way, I'd make sure to keep some extra time/cash put aside for some basic TLC (fret de-burring and polishing, filing down 'fret sprout', truss adjust, etc.)