Older games need going through by a competent tech/enthusiast. For a lot of people in the hobby, that's part of the fun. Once you go through and bulletproof everything, they are just as reliable, if not more reliable than a newer game.
Aside from gameplay opinions, older games can hold their own. I have had JJP, Spooky, SAM Sterns, 80s Ballys, 80s Williams, WPCs, and a Gottlieb/Williams EMs. I guess I don't get where the reliability factor becomes an issue once you honestly resolve a problem.
If you're looking at JP2 as a new purchase, I wouldn't worry for the short term (next 5 years?) as from what I see, Stern's CS seems to be pretty good. If playfield quality is a concern for you, you might be better off buying used where you can inspect the game, vs NIB.
