... still has a long way to become useful in Revit. Maybe for simple, regular elements it is solved but for actual more complex projects it is quite difficult (=impossible) to be done. And I'm not talking about detailed issues like clashing of rebars which could be solved manually (as far as I can tell), but of actually inserting rebars in a complex shape. Just take a bridge pile as in attached pic and try to fix some reinforcement, you'll see my point: out of 8 rebar types I cannot properly fix 5 types and I just started it.
Also, once this is fixed, for sure many of us will ask for some better 2D representations of the 3D reinforcement but baby steps will do for now...
I am using 2018 Revit.