The Juicy Lucy is fantastic. Not the best burger you will ever eat, but not a far cry from it either. It is griddle cooked very slowly, with cheese in the middle of the patty. A simple burger that tastes great.
However, I'd recommend 2 things:
1) order the burger by phone in advance as it can easily take them 15 minutes to get it ready. A big frustration, easily avoided.
2) eat the burger straight away when it's fresh off the griddle. I wouldn't take-out, as the cheese will dry up quickly.
With regard to the potatoes, I am personally a big fan of the Tornado. I know many people don't like it, but I think it's great with a little sour cream.
I'd definitely recommend this place!