Some of my friends have been unable to get to the Dragon Isles, and getting world server down errors. My server is full and I got in fine as well.
But yeah it feels more like MoP and Cata than the last several expansions, adventurous as you said. No borrowed power, no mission table, no tacked on big feature that will be gone next expac. Professions look promising. Talents are great, The story is interesting so far, nice to get some focus on the dragons and the aspects. Dragonriding is so cool, and there are even races, I love it. Renown, and levelling your Dragonriding, being able to customize your drake.