No matter how I love PoE setting, I consider Tyranny as the best game out of three Obsidian gave us last years. It has immense amount of amazing mechanics (tho unfinished like was said by many in this topic), way better approach toward follower affinity, more symmetric combat where hostiles use abilities on par with your party, game events are more dramatic and player's choices matter like nowhere else. It is a shame that kind of unusual approach toward game content where you can not see even half of it during one playthrough and overall game shortness killed it for majority.
But I am still sincerely baffled why even some small gems from Tyranny that were easy to transfer like artifact mechanics, passives with spectacular 2-3 hits animations (instead of boring plus to some stat) or reputation related perks didn't make it to Deadfire.