Installation process:
No Problems at all. Easy peasy lemon squeezy.
Activation:
We are used to that.
Had to activate all workflow Actions. They all were disabled first.
There won't be a Workgroup Edition I heard. Is it still necessary to activate the site Feature then?
New Action design:
Fancy look
I am glad you did not rename them so I still find them using the search box.
Will there be one design for the same Actions across all platforms? (<SP2016, SP2016, O365)
Webparts:
I am glad, Nintex Forms and Workflow Webparts still will be available. Nice!
Overall:
Good, stable, solid Impression so far. Good Job!