I have used all of the forms components available to Joomla! sites and this one is the one I keep returning to. If you need a simple form builder the Quick-mode version of this component is ideal. Plus,you can write your own css for the quick-mode template and assign it on a per form basis. I have gotten into the habit of loading Breezing forms as soon as I begin a new site and creating a new css for each type of form that I use. If I have to develop something with a more advanced layout then the classic mode easily accepts html in its label fields.
It would take too long to write all the flexibility this form offers-but I must say adding scripts to the functionality is well documented and the supporters will respond to questions.