So after posting here asking if I should give D3 another go, initially the response from everyone seemed luke-warm, so I ended up trying Path of Exile instead (had barely heard of it before, but it was free so figured why not give it a shot before shelling out cash to catch up on D3 xpac(s)).
Holy shit, PoE has been everything I ever dreamed of in a game like this. The item/crafting/skill system feels like they took everything that was amazing in D2 and then multiplied it 100x depth wise. I feel like I could nerd out on it for years to come. I would be curious to know how D3 has evolved since release in comparison. I would love to have a game with the depth of PoE but the level of polish Blizz games are known for. That said, I feel like a lot of the PoE-esque mechanics are probably too unfriendly for the more mainstream audience Blizz goes after.
I wonder if some of the deeper mechanics that exist in PoE will make it to D4 (if this stuff isn't in the more recent versions of D3 already).