I had some reservations due to the Titan Quest connection.
I found TQ rather bland and boring, never-changing button-mashing without any challenge whatsoever. Uninstalled it during the 2nd world / act.
Then I got talking with one of the GD devs who had basically the exact same opinion!
The plan is to make Grim Dawn more "involved", so it actually matters what active skills you use.
Within reason. Not all classes will be so dependant on active skills, creating actual diversity in gameplay.
They just don't make these kinda games any more. 
Grim Dawn and Nekro (another underrepresented genre) are starting to look very much awesome.