With this extension you can not only build your own applications (i.e. input information, process that information, then display it for all to see), but tie together and process information for almost any joomla extension out there! Have a component who's form is buggy, or one that doesn't have a form at all? Then you can use fabrik as a way to input information directly into that components database, and have it show up when viewing that component on the front-end! How about a unique profile system? I used this feature to build a user banner advertising interface that ties in with yet another component I have.
Of course, like any program that is worth having, it will take time to understand and to fully grasp the entire power Fabrik. But even if you're just starting, the support, documentation, and tutorials will get you going right off the bat.
All these previous 'poor' reviews are simply people being too lazy to take the time to completely understand what this extension can do...and for free (though with the 'bronze' membership I am getting daily! support--which is almost unheard of). Bravo to both Hugh and Rob for creating something that not only ties all of the extensions together but truly harnesses the power of the entire Joomla! platform.