Yep, way over thinking it. You've sailed 20 OD classes? And still can't find what you're looking for? Paralysis by analysis comes to mind…I have stats in a spreadsheet for 83 dinghies and skiffs in case you are wondering how much I have thought about this.
You seem to have a shortlist of maybe 3 boats (MPS, Franken 29er, EvoVX). Create some criteria, give them scores, see which comes out on top. Likely you'll still just buy the one you want on a whim or the first that comes available within reach at the right price, or maybe has the best community nearby.