On the contrary, I don't share the opinion that Gundogan isn't good.
In comparison to Dihno, I think he is a better passer out of tight spaces, has better peripheral vision, has better dribbling skills, moves around better to make himself an option for a pass and has better control and technique.
He is weaker in the tackle, slower to react defensively, weaker in the air and not as good a presser.
In the end I think performance wise it will come out a wash. Folks will whine when he doesn't go full throat into a tackle, but they'll miss how we keep possession longer and more comfortably transition from defense to offense. The results will stay about the same while folks are busy hoping for Dihno to get back soon.
I think that is an almost perfect analysis of Gundogan's game.