I really dislike what they did with the questing. It started with the revamp of old Azeroth during Cataclysm and got added to MoP. The questing is put on a set track, a train you have to sit in and follow as it handhelds you throughout the questing. No exploration of your own at all.
Legendary quest was pathetic, and I really, really hope they scrap this idea for future legendaries. How many is it? 3 different quests to collect X amount of items, 1 quest to gather 3000 Valor, and of course they slapped in a reputation grind for the Black Prince. All of these quests being time gated and boring as hell.
Raids became really uninteresting with LFR, and you were forced through it. ''You are not forced to do LFR!'' YES, we are, since the items in there are too good and we have to get them to raise our Ilvl and DPS by a lot.
Heroics became a joke, pathetic. Far too easy that you are even able to join up as 5 DPS and do just fine.
The only thing I liked was Brawler's Guild.