To offer a counter-opinion:
I played 2E in high school, missed most of 3E (except for the computer games loosely based on that ruleset, which I love and still play today) and these days play 4E. I've played a couple of encounters with the 5E playtest bundle.
My group play D&D more as a tactical skirmish game than as an RPG. We play RPGs too, but we tend to use indie or White Wolf (does White Wolf count as indie these days) systems for that. D&D 4E as a tactical skirmish game, is awesome. I'm not sure if you'd consider my style to be "adversarial" DMing. I'm certainly deliberately trying to bring the team down in combat, but I'm not trying to "beat" them - I'm the DM, if I want to "beat" them, rocks just fall.
A perfect encounter, for me, is when the party beats the monsters with no deaths, but feels like they only just pulled it off. A perfect adventuring day is when the whole party finishes the last encounter for the day with no surges, and dailies used. If I've killed one of them, I've failed; if they haven't been challenged, I've failed. If they've felt like they were on the edge of disaster the whole time, but pulled through by the seat of their pants, I've succeeded.
5E is not the edition for us. Like you said, it's clear and simple, streamlined, and without as much math, but we enjoy the complexities. We like the billions of permutations 4E offers for characters, despite the balance and function issues such an array of options present. For me, 5E doesn't have the in-depth combat complexities that 4E offered as a skirmish game, but neither does it have the narrative elements that support role-playing that systems like Fate, or Storyteller do.
That aside, I still wouldn't be buying 5E, simply because I no longer trust Wizards management of the brand. I avoided the 3/3.5E debacle, but 4E was just as poorly managed. There are whole classes that are practically unplayable (Seeker, Runepriest, etc) because WotC decided to switch to Essentials mid-stream; others were neglected ever since they were printed (Assassin, Artificer, etc). Martial characters got two hard-cover Power books; every other power source got one - classes that were printed after their power book got zero. Dragonborn and Tielfling were the only races to receive dedicated books, giving them far more options than other races. And that's aside from stuff like expertise math-fixes due to insufficient QA in the first place.
TL;DR: I'll keep 4E for a skirmish game, and keep using indie systems for role-playing. 5E fills neither niche.