If you're looking for a perfect working, easy-to-use and well supported form-plugin, this is the right choice! I've tested a lot form-plugins and this is definitively the winner. It's very easy to use and provide a lot of functions in the same time! And the best thing is: The author respond very fast on bugs and suggestions and will help you with all you need :)
At last but not least, the ajax-based form configuration is wonderful!