I have been using Breezing Forms for about a month, and it is the hands down best one I have used. I have tried several, but this one has the most advanced functions and is easy to use. I have not even touched the surface of the capabilities of this module, and it has already allowed me to have multi page form(that saves data between pages), hidden activated fieldsets, customized themes, database storage, etc.
Support is excellent. Response is fast and they work with you to get the answer you need. They also have a good KB and forums as well.
I cannot wait to explore this module and find out its true capabilities.