I kept hearing how "amazing" this place was prior to our trip, so I was a bit disappointed, but the burgers are good.
They have a good selection of unique burgers - things like teryaki, pineapple burgers, etc. - that are very good but quite expensive at about $8 each.
They've also got a good selection of milkshakes, fries and other sides.
One thing to be aware of: It takes about 20 minutes to get your food. After reading the Kauai guidebook, apparently this is a known fact, but we were a bit frustrated, as was the couple next to us, who went up the window to complain.
If you love burgers, check this place out, but otherwise I wouldn't recommend going out of your way.