Oddly enough, a buddy of mine convinced my secondary group to drop their current HeroQuest Revised game and try a "gritty," low-level, bog-standard D&D 3.5 game. (My primary group has all fallen under the spell of Savage Worlds just like I have.)
And unsurprisingly, my feelings of having "moved on" from 3.5 to systems that just work better for my playstyle remain completely unchanged.
I was already on the fence when it came to 5e. I was at least considering picking up at the minimum a 5e PHB. But this "retro" attempt at trying 3.5 again is pretty much the nail in the coffin against it.
Frankly, I just don't like "D&D"-style RPGs much anymore, which is a monumental thing to say if you'd known me back in say, 2007. To say nothing of the fact that, good heavens, after nearly 15 years of people taking the opportunity to improve 3.5 at every turn--and a lot of people succeeding, like Fantasy Craft and Radiance--plain old 3.5 is just frankly, clunky.
It's obvious to me now that so much of what I thought was great about 3.5 was just that I didn't know better. The skill system now just feels clunky. The class progressions and save progressions feel clunky. Hit points feel more unrealistic and clunky than ever (it's probably my least favorite part of Savage Worlds, but I still vastly, vastly prefer Savage Worlds shaken / wound system to straight hit points). The whole concept of "armor class" now just bothers me (armor should be DR, and defense bonuses should be calculated separately).
And I never really liked Vancian casting, even when I was actively playing 3.5. Back then I mostly just tolerated it. Now what was once mild annoyance has blossomed into full-on, unabated disdain. I truly can't can't stand Vancian casting anymore.
At this point, the only scenario in which I could see myself running or playing 5e is if my primary group decided they wanted to try it. I'd be willing to go along, and at least pick up the starter set and a PHB. But frankly 5e is at best 5th or 6th on my "Systems I'd like to try out" list, behind The One Ring, Burning Wheel, FATE Core (or Legends of Anglerre), Night's Black Agents, or Runequest. Heck, as much as I have a love / hate relationship with Fantasy Flight as a company sometimes, I'd probably rather try out Edge of the Empire, Age of Rebellion, or WHFRP 2e or 3e before I played D&D 5.