I've done about 22 of the MSQ so far in Heavensward, gotten a chocobo that can fly, and started working on the quests to unlock flying.
I took some time to try out the Machinist and Astrologian jobs. I still prefer the Samurai over all the other jobs although I have dabbled a little here and there with red mage. Honsestly, I like the simplicity of the Samurai's combat rotation. It works for me.
Looking at the wiki, I see that the MSQ for Heavensward is laid out in level ranges (like a set is for 52-53, 54-55, etc). I am assuming that I can I mainly just do the MSQ quests in Heavensward and expect to get my main job (Samurai) to 60 by the end of it similar to how ARR worked out.
Over all, I'm have a good time in Heavensward.