We've been here a few times to eat in and for take out. Fatburger is ok. Not awesome, not crap, but ok.
I think to be honest price has a lot to do with it. I should mention that I spent over 10 years working for a "gourmet burger" chain in Ontario, in the stores and later in the corporate offices. So I get food cost, wanting to offer a better experience that McDonald's and be more upscale. And I think that is where Fat Burger falls down. While they are better than a "cheap burger place" but they fail to "wow" me. So then you become very aware you just spent $30 for a couple of burgers, fries and shakes. Better than McDonald? Yes. But I think they are over charging. They aren't THAT much better.
That being said, the food is decent. I would recommend eating in because they haven't quite mastered the art of packing up food to go-it comes out of the bag an absolute disaster. The burgers are good, the fries however leave a bit to be desired. The Chocolate shakes are also good and very filling. The turkey burger is a tasty choice if you are looking to avoid beef.
It would be nice to see Fatburger either lower their prices slightly, or improve their "wow" factor somehow to justify their prices a little more. We'd probably go more than once a year if they did that.