Ordered The Works and it was great. A friend who's been to Philadelphia confirmed its authenticity. I gotta say, this is pretty much the greasiest thing I've ever eaten but I couldn't get enough. Every bite of cheese whiz, shaved steak, provolone cheese, onions, and green peppers was to-die-for. I would definitely go back.
Tip: They also sell some American drinks, like Yoohoo.