I use it for validation only . Seriously, it takes several times longer to create a form with this that it does just to create all the fields in Dreamweaver (About 1 - 2 minutes) create a couple of css classes per form element, and then set the validation.
Compare this to how long - on average - needs to be spent wrestling a CSSFB form in to shape . Why are they so LARGE? Why do they have to fill a page? Why is the finished css so immutable?
Looking at the sites that are posted here - you can spot a CSSFB form immediately. It's the form equivalent of of cutting a hole for your letterbox the size of a man-hole cover in your front door.
I am pleased to see that I'm not alone thinking this. WA fellows please update form builder!