I moved to Pittsburgh in 2002. It doesn't matter what online voters on a Yelp-like app determine is the "best". Using my current city as an example, you could easily get a top 10 where someone who grew up on Wooster St pizza would throw out all 10 after one bite.
This place is a hugely popular local institution. If you were born and raised on CT pizza, you are likely offended that this is called "pizza".
It's not that there isn't good pizza here. I have a handful to choose from within a couple miles. But the ones that most resemble what you get back in CT are not popular here at all. In a recent reddit meetup to determine Pittsburgh's best pizza, 20 pizzas were entered and a Costco pie ended up in 2nd place. My two favorites were both in the 15-20 range (the only ones with bubbly crusts and some char).
Better to come over here to BY, state where you're going and ask for pizza recos from people who are more likely to share your pizza heritage than go on an app that is more likely to lead you astray than feed you decent pizza.