Dublin is a lovely city, very international and The Convention Centre Dublin was an excellent location. Dries keynote was less enterprise oriented than others and helps to understand where he wants to take Drupal8. The most interesting thing for me is to see how the new life cycle of D8 roll-out is. There was more about D8 new development cycle on the session "Drupal 8's rapid innovation promises".
From the sessions I went to I recommend HTTP2 and JSON API. I also assisted to console sessions, from those two the one I liked the most is Learn the new things in Drupal 8 via debugging. There were other interesting sessions, but haven't got the time to go through the online material yet.
I was particularly interested in a new topic called "Offline first". It is a very interesting API that allows you to take your site into a cellphone and make it work like an "application" so it will work even without a network. The first part of the session explains this in more detail, but if you want a closer look I recommend to read the material the speaker shared.
Sadly I don't have the same level of enthusiasm I had at the end of other Drupalcons. Work is a bit hectic right now and I didn't have the time to participate in the sprints as much as I would have liked. That's probably the reason. But as always the experience is positive and leaves you with new thoughts.