This is by far the best forms plugin out there. I have worked with plenty of forms plugins and the functionality has always fallen short when it comes to doing anything even a little advanced. But WS Forms is my sole choice as it never comes up short. This can be used on commercial-grade websites; I am using it for a client’s insurance website with over 100 fields with very complicated logic, and it simply works.
I should also mention support is fast! I had a weird issue, reached out to support and they pushed an update that same day as a quickfix.