It seems to be that every extension in this category seems to be very easy to use :)
I tested some of them and this is realy easy to use and my favourite.
i was able to build a good working form within five minutes. the only suggestion i have, or better a wish is for more customizing functions for the layout.

This extension is a must have for every Joomla user. Without this extension joomla wouldn't be that sucessfull.