I used to go to high school right down the road from there! Fun seeing my old neck of the woods on the internet. And yeah I've eaten there. White Manna is everything White Castle wishes it was.
The one time I've been here, the sliders were really good, but the service was weird. They served some regulars before us and we got our sliders after ~20 minutes.
Maybe I am too spoiled by White Rose System in Highland Park?