We've been using Formscentral quite intensly for the last year. Of course, all good things come to an end, and I've started the search for a replacement.
After looking through the competition, I've so far not found a solution for something we need:
Backend editing of fields
We use formscentral partially in an authorisation flow and additional data input. Basically one of our employees submits a request (by inputting a form). This form has a few hidden fields which are used in our backend to allow our teamleaders to approve and to fill in additional data. This additional data is entered in fields we created in the backend of formscentral per form. This feature is something I have not found so far with the competition.