I kind of liked Titan Quest, at least the skills and class progression, not so much the story. And I was really sad when the studio closed door. I kind of dismissed Grim Dawn though, because it looked like a simple indie hack&slash to me.
But Grim Dawn website mention these in feature list: "New quest and conversation system will allow players to choose quest paths and rewards, interact with NPCs in more interesting ways, and an intuitive quest creation wizard will make life a lot easier for modders." & "An NPC faction system lets the player improve their relations with different NPC groups to earn rewards as their favor increases such as merchant discounts, new items, and additional quest lines. However, aiding one faction could turn a rival faction into your enemy. Choose which side you will support!"
Seems like it might be worth it to keep an eye on it.