Diablo III really has nothing on Path of Exile at this point other than graphics
You said you haven't played Path of Exile in over a year? Well, that's a mistake most people make when they cast judgement on Path of Exile. In the past year they revamped THE ENTIRE Endgame system along with adding subclasses that further provide more build diversity, and what has Diablo III done since then? Added a new season, a paid character class, and a special throwback event. The PoE developers truly love their game and community and aren't muddled by corporate greed or anything that has crawled up Blizzard's ass recently, and will continue to update their game with meaningful features.
I know you're probably talking about Diablo II but at this point Path of Exile and Diablo II are almost head to head in terms of quality of the gameplay, hell most of the team that are developing PoE are hardcore Diablo II fanatics/developers.
This game text a little while to REALLY get the swing of things IE the gems/skills linking them and how to read em. The passive tree, the ascendancy classes, flasks and the end game stuff ect ect. And of course the path of exile currency. Once its all understood its beyond fun, like...beyond fun and I still play Diablo I/hellfire Diablo II/LOD and two on going mods for each game and this is my favorite Action role-playing game but right and barely infront of Diablo II.
Fun fact: David Brevik one of the co-founders of Blizzard and the creator of Diablo actually went on to be the CEO of Gazillion Entertainment who made Marvel Heroes 2016 which is an MMO marvel version of Diablo, then left the company a year or so ago and now is on the Path Of Exile team.