I mean I find so obvious usability problems with it that really makes me wonder. For example suppose you want a workflow for adding and approving a new Item. Then you find the following problems:
1) It is not possible to cancel a workflow or skip a step, you have to finish it or it stays open.
Suppose you want to have a workflow for a member of Sales Team adding a customer, then the Sales Manager updating it with the credit limit and then accounting team updating it with other data.
2) If you start the workflow manually you MUST add a new customer, you cannot realize that oh I have added it already so change it to an update step. Then in the next step you must do the update even if you realize that adding the customer was a mistake.
3) Maybe it works better if you start it a conditional way, automatically but then you must wait 5 minutes until you can update. Maybe you can have a dummy customer card that you update with something if you realize it was a mistake and just want to close the workflow.
In my opinion the workflow is not useful until they make it more flexible, be able to cancel it, to skip a step, to do an update even when the workflow wants an add, and so on.