I really like 4e. It's my current system of choice (we'll see if 5e can dethrone it someday, but for now it's too sketchy and awkward).
But I've had a lot of back-and-forth with some of 4e's biggest fans because some of the things they find most beloved and intuitive about the system are things that punch my happy fun elf times in the face hard and repeatedly.
I see 4e's biggest strength as its mathematical underpinnings. I wouldn't call it balance, I would call it
predictability. 4e's bend away from swing and toward a quantified experience (1 hr combats) made it easy to understand the underlying elements at work in the numbers.
And once you have a numbers system that works, everything is up for grabs.
Combats too slow? Speed 'em up, predictably.
Want some more swing? Rip out the system's training wheels and go wild.
Want more in-character elements? Layer 'em on the numbers, man. The numbers are meaningless. They're placeholders. They're a pacing system when you get down to it, and like any pacing system, you can interact with it and disrupt it and make it do what you want. High point here, low point there, steady build between these two points, BAM.
I find that for me, 4e's biggest weakness was its "one true way" ism. There's no reason that 4e HAD to be a game at its core about ADEU, Healing Surges, Martial Dailies, Inspirational Healing, Morale HP, skill challenges, Forgesqueries, Dragonborn, blink elves, or any of that rot. 4e *should* have been a game you could play without any of that (arguably, it should have been a game you could play without any of that
at launch). But rather than providing a real, systemic alternative, 4e became too conservative to do anything other than basically the same thing with slightly different keywords and color palettes most of the time, and always revolving around splats that added hundreds of combat options and, functionally, little else. 4.5 was a bit of a step away from that, and 4e grew more comfortable with adding a lot of fluff onto those combat options, but even Essentials and late 4e books like
Heroes of the Feywild couldn't shake the lingering bounds of the system it was embedded in. There was a "Right" Way To Play D&D in the 4e era, and people who didn't want to play that way were not given any sort of real, official support.
Most of the things that 4e wound up defining itself with are things that I don't like about 4e, and can totally understand when people give up on the game for doing it (even if it's not always so severe for me). But for all of its desperate, pleading insistence that you play it in this specific and narrow way, I find that it shines for me best when I strip all that away to the naked core of the thing, and make THAT sit up and beg for me.
Which seems to make me an odd duck in the D&D world. I don't think I'd DM Pathfinder if you paid me, but what 4e's most ardent fans rave about and what its publishers insist on are the superfluous things I can't get rid of fast enough. The delight I have in 4e has jack all to do with it "finally delivering on D&D's promises" (as if no one told an epic D&D story before 4e came along), and 100% to do with that "I know Kung Fu" feeling you have when you know with a high degree of precision where you can press and tuck and cut to produce the effect you want. And 4e makes that easier and clearer than any edition before it -- and quite possibly trumps 5e in this regard too, though time will tell. I'll take the "9+ hits" and I'll leave the morale HP. I'll take the "5 encounters before a full recharge," and I'll leave AEDU.
Give me the Nentir Vale, and I will burn it to the ground. Give me Page 42, and I will build empires that stretch beyond the stars.
I'm still pretty optimistic about 5e, too, despite some recent heartbreaking news about second wind and tieflings.
