"Standard SharePoint forms leave something to be desired, especially when it comes to building in logic and customizing the layout. One of my acid tests for any form-building product is to see how it handles parent-child data (for example invoice and invoice line items). Once SharePoint lists are setup, you can configure and deploy a form, with logic and basic workflow in only a few minutes. Parent and child data is handled with ease (but only one level deep). One the most awesome features of Sintel is the ability to inject whichever custom JavaScript you want into the Sintel form – so if the Sintel form doesn’t do it out of the box, it is fairly straightforward to add it in yourself. I contacted Sintel a few times with what I considered to be bugs, or to request features – and all were sorted out within a few days. Sintel is a great product to produce SharePoint forms with a bit of complexity to them."