Just okay. During a recent visit to Longmont, I ate twice at Old Chicago. Each time I had one of what they called their "artisan" pizzas. One was prosciutto and mushroom, and the other was pepperoni.
I am a Chicagoan. That means I've eaten a lot of pizza. A lot. The prosciutto and mushroom was the better of the two. It had a strong but subtle flavor. The crust was well-cooked. I liked it a lot, and would have it a again.
The pepperoni on the other hand . . . meh. A lot of cheese. Not a lot of pepperoni. And what happened to the crust? It was kind of mushy. Disappointing. It was probably better than you'd get from a 7-11, but it certainly wasn't better than any other slice of pepperoni pizza I've had in my entire life.
Service was fine. A waitress named Jess was very professional and prompt.
Decor is very traditional Chicago-style stuff. I thought it was very ironic that I traveled a thousand miles to eat Chicago-style pizza. And the place does resemble oh so many pizza places/bars in and around Chicago, so I guess you could say it's authentic. The menu does include deep dish pizza and Italian beef. If they included Chicago-style hot dogs (no ketchup, with celery salt, on sesame seed bun), they'd complete the trifecta of traditional Chicago high-caloric food.
I did not have beer, so can't comment on that. Would be nice, though, if they could get Old Style. Now that's Chicago!