Playing Pool Of Radiance got me learning the ins and outs of 2nd edition AD&D and I came to the realization today that I prefer games with a magic points or mana system. Probably because I grew up with JRPGs which exclusively deal with MP over spell slots. Don't get me wrong, D&D is great, but it's such a pain when you get into battle and you realize you forgot to memorize Detect Magic and now you have a bunch of potential good loot.
It's a role-playing game, why would you try to find the most effective class? Pillars of Eternity had a system where every class and every stat was supposed to be equally viable and as a result, none of them are memorable or really stick out. Besides, mages can only do what they've prepared each day; the power creep is another issue that magic points on their own don't fix (see all the arguments about D&D psionics).