Considering graphics, I think that technically it's really good and the art style is a matter of taste. To me it looks amazingly good.
Heck, Titan Quest still looks really good even now, almost 6 years later.
In fact, I'd say it looks as good if not better than Diablo 3 at the same zoom level - and it definitely runs a lot better (constant 120+ FPS in Titan Quest: Immortal Throne at max settings with AA versus ~27 FPS in Diablo 3 at max settings without AA... and that's not taking into account the net lag issues D3 suffers from).
another generic ARPG
As for calling Grim Dawn generic, it does quite a few things differently to other recent ARPGs:
-> Non-linear progression
-> Post-apocalyptic fantasy Victorian era setting
-> Combine any two of five character classes, each with their own fairly large skill tree
-> Faction system