When a visiting relative was craving a White Castle Hamburger, we decided to try Krystal. The only White Castle in Lake Mary, FL that I knew of is seen in the picture below, but that house isn't serving hamburgers, so Krystal the next closest thing.
I ordered a combo that came with a chicken sandwich (known as Chiks), fries, and a soda. After about a ten minute wait in the fast food restaurant (we were the only customers), the food finally came, and I was surprised to see that my combo actually came with three chicken sandwiches. That's more fried chicken than anyone should be eating in one sitting. One sandwich and the fries would have been enough fried food for me. The sandwiches weren't horrible, but they were kind of salty. They reminded me of the sandwiches from the Chick-fil-A next door.
The final verdict with the miniature hamburgers was that Krystal doesn't come close to the awesomeness that is White Castle (although I can't say personally. I've never tried a White Castle).