I appreciate what Aurich is saying, and his point is valid, but that logic would suggest that a potential buyer avoid ANY games from any company other than, maybe, Stern. (Even with Stern, there are concerns about availability of game-specific node boards a few years out. I know of customers who have waited months for replacements for node boards for Sterns currently in production!) It's not even just PCBs ... for example, if your game's plastic ramp suffers a large break, is an OEM or repro replacement available?
So I suppose if your absolute top priority when buying a game is to ensure that the game will be serviceable for decades to come, stick to EMs or solid states where you already know that all replacement parts are readily available. Otherwise, it's difficult to do more than look at the present-day reliability and customer support of any game, because it's just a gamble to predict what's going to happen 5+ years down the road.