Long time player of D&D, I GM'd all editions (OD&D, D&D, ADsD1, AD&D2, D&D3, 3.5, 4, 5) and hated DD3, DD3.5 because they were unnecessarily complex rules based on an exception-to-rules systems that is unbearable long term. I hated DD4 because it felt mostly like a boardgame. I hated PF because it was DD3.5 on steroids in terms of rules, plus it told me how I had to run a game if I wanted to be part of the "PF players matching system" or whatever. I bought them, played them a few games, sold them back.
So I continued playing ADD2. And even reverted to Rules Cyclopedia. I don't need to have a fuckton of rules to tell me how to run a game. I also tried various other OSR games and variants. Burning Wheel/Torchbearer was very nice but my group had a hard time to adapt to some concepts that are very different from D&D. Dungeon World was a blast, still.
When D&D5 came out, I bought it thinking "I'll probably sell it in a few weeks anyway". And it's a blast.
It's D&D2 with a few good things taken from later editions, without all the useless goo that are prestige classes and feats.
D&D5 made me sell my Rules Cyclopedia, which I had not thought to be possible.
Better : there is only ONE book of rules (the PHB), with DMG and MM for the usual triptych. The rest are campaigns and good ones at that.
Even the starter set is very good : it provides a very nice small campaign for levels 1 to 5.
Tyranny of Dragons is weak. Many chapters are "repeat previous chapter" : find the cult, infiltrate the cult, get a clue for next cult.
Curse of Strahd is a very good reimplementation of I6 (better than the DD3 one was).
Out of the Abyss is excellent (thinly based on Scourge of the Slave Lords). Players wake up as slaves for the drow in the underdark, break out and flee until they find an exit but have to go back because (spoil).
Princes of Apocalypse is a reimplementation of Temple of Elemental Evil but better, with the temples separated over a region to visit.
The Storm King one (thinly based on Against The Giants) is the weakest, IMO, with a few things that are over the top (a flying tower with a big wizard hat on top of it - I know it's canon but that is what I dislike in the FR).
The Volo's Guide is not very interesting.
The Guide to the Sword Coast has interesting bits in it but is aimed towards new GMs with a lot of very basic info.
The next book is a reimplementation of old modules. If it's just an update, I'll pass because I've already run them all at least once and don't want to do it again. If it's a real reimplementation (like Strahd), I'll buy it. It's the first book I have not pre-ordered.
I hope they'll bring back old settings. I'd love Dark Sun, Planescape, Ravenloft and Birthrigt to make a come back... i'm wary, though: the DS version for DD4 sucked...