My experience with Gravity Forms

Has anyone else used Gravity Forms? It’s a WordPress plugin for creating custom database backed forms. It seemed initially quite powerful until Speed Test I struck some bizarre limitations. Here is short list:

Their is a total field but no subtotal field.

Updating a form does not instantly update Scrabble Word Finder its preview, even with a hard refresh of the browser.

Calculated fields have no option for providing if-else logic (only if) therefore feels like crippleware. There seems to be no workaround either.

I am therefore wondering if I must learn the gravity forms API in order to create a custom field type (with if-else) logic or whether there is a better way?