I usually eat at their other location near my house in Henderson which also serves Pizza, but this location is just as good, and 95% on the authenticity scale
Gonella brand Italian bread is what most places in Chicago use but it's impossible to find in the west and cost prohibitive to ship. There probably is another brand of bread that's available around here that's more like Gonella which would boost the authenticity rating up a notch or two, but with all of my nit-picking aside Windy City is a great choice, and in my opinion even better and more authentic than both Rossatis's (pizza pub) and Al's (which is supposedly a Chicago tradition and recently closed up after 2 years of business in Las Vegas)