The Thunder King I felt like came off as weak because, while he has an interesting backstory, he didn't do anything noteworthy in the PRESENT other than sit in his evil island. It's like they tried to replicate Yogg-Saron, a villain you know nothing about coming into the new continent but learn more about as you level across the zones, do quests and learn the lore, but while Yogg came across as a great and present threat, the Thunder King kind of fell flat because everything he did that was noteworthy was done thousands of years in the past.
The Sha, Mantid and Kor'kron I like though. I don't mind stepping back a bit and lowering the scale of the conflict a little, because honestly you can only keep the escalation up for so long. It's nice, for one expansion, to not be killing off one of the series' most iconic villains and focus on some newer lore. Sure, MoP's story isn't perfect, but I love the change of pace before we inevitably head off after Azshara/N'zoth/Kil'jaeden/Sargeras/whoever is next on the chopping block.
One thing I do miss however, is the neutral cities. And I mean a real, fully fleshed out city like Shattrath or Dalaran, not two cut and paste mini cities. It makes sense I guess considering we're at war this expansion, so a neutral city wouldn't much fit with the Pandaren themselves not having a big capital, but I hope we get another one next expansion since the Horde vs Alliance story will no doubt be toned down after the Siege.
Part of me misses new dungeons, but to be honest even those get old fast when you're chain running them to catch up an alt or to farm valor, so I don't mind them using scenarios instead. Scenarios are one thing I really love about this expansion as well.
As for thinking Blizzard made MoP to cater to the Asian market alone, I have no reply that would be civil enough really :P
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In spite of the many heroic and powerful deeds, our factions have left Pandaria in ruins and turmoil. I think that was supposed to be the point. Although I don't think Blizzard was able to convey that message very effectively.
Buying rep items with gold. The double gating mechanism for rep gear is awful and I'm glad they're scrapping it, to an extent, in 5.4.
HEROES NEVER DIE
Longer and harder leveling, it's far too easy now.
Rare mobs being no threat at all.
Group Quests, will add elite zones into this bit (think of that Hinterland's area in vanilla).
Harder 5 mans.
Multiple starter zones and different leveling paths. I would like at least a choice of 2 zones for each level.
Talent point for each ding.
At least they got raids right.
Arena of Annihilation is meant to be the next version of "arenas with weapon rewards" - it might not feel the same (it doesn't to me) and hopefully next expansion will introduce the old style arena, but we can't say, it's not there.
If I remember correctly, I took a warship to Pandaria for the first time, and then there is the portal (same like cata portals from main city) - so O.o huh?
It seems you miss things that can't be missed, since they are present. To your question though, I really miss epic catchup with 5-mans (last tier cata dungeons + zuls were amazing and actually pretty challenging) the same with WotLK ICC dungeons. I also miss epic gems dropping in 5-mans / raids (not only the recipes, but the actual gems, like it used to drop in BC). Aaaaand I miss reputation tabards.... 'nuff said.
But on the other hand, we got plenty of new stuff, scenarios, interesting dailies tied to content and story, world bosses (I love world bosses), tons of rare mobs and even zone event (battlefield: barrens).. I think if they create a mix of these and add something from the past, it could lead to a pretty amazing next expansion. My hopes are still with Blizzard.
Lack of 5 player dungeons and the way the current dungeons are just too easy. I'm not saying they have to be really hard but it's basically impossible to wipe at the moment...
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The one thing I do miss is dungeons from BC/Vanilla that required some strategy and planning. Having a hunter kite one of the adds on Drakkisath, actually using CC, longer dungeons like BRD. I understand the design intent behind faster dungeons, but I still miss some of the dungeon runs I did in vanilla and even BC. That said, even in BC as a prot paly I was aoe tanking most stuff in heroics once I got somewhat decent gear anyway so long as my healer was also decent.
that means: I wanna see the Burning Legion, I wanna fight demons and I wanna learn more of the titans (granted, we got some titan lore this expansion, which was good!) Also the whole acopaclyptic feeling simply isn't there this expansion. to me warcraft always had a dark, grim feeling, now we hunt bunnies, apes and cuddle with pandas, even the mogu don't look frightening at all, only the mantid were cool, but their story ended way too soon imo