-Global Cooldown- Almost all spells are now on the global cooldown. This has slowed gameplay down quite a bit and you won't get to use the full potential of your spells cooldowns. For example, you cast a spell that increases your damage for 15 seconds, after the global cooldown and you're able to cast again, you now only have 13.5 seconds to make use of the remaining time. There are far too many spells on the global cooldown that shouldn't be.
Keep in mind that these quests are optional, and are not necessary to continue leveling and capturing companions. They are also account-wide, so if you complete the quest chain on one character, you will not be able to complete it again on another. However, any progress that you've made will be saved and you can pick up where you left off in the quest chain on another character. The dailies that you've unlocked will also be accessible by all your toons.
Then 8.0 came along and turned everything on its head. Most of the techniques and shortcuts discovered, after 7.3.5 introduced scaling, were nerfed into oblivion. Many of the old techniques were confirmed by myself, first hand, to no longer work. I'm hoping that this thread can serve a similar purpose as the old thread, and gather as much data as possible on the fastest methods under the new system, and facilitate as many different perspectives and opinions on speed leveling with constructive discussion. I've just finished leveling to 110 under 8.1 with the exp curve.