I tried Primanti Brothers when I was in Pittsburgh for an Eric Clapton concert. Like many tourists, I tried Primanti Brothers because I saw it a thousand times on TV. The particular location I went to is tiny - much smaller than it seemed on TV. Regardless though, the sandwiches are pretty good.
I sat at the bar and ordered the pastrami sandwich with the provolone, slaw, fries and tomato. The slaw was exactly how I like it; vinegar instead of mayo is the way to go. The fries were pretty good but not amazing. Not sure if they double-fry the fries but they needed to be a bit crispier in my opinion, especially when you consider that they will get automatically soggy on the sandwich. The pastrami had a nice taste but could have tasted more "homemade". The Italian bread was a nice touch, but eat quickly or the bread will dissolve into the meat/slaw.
Two complaints. The sandwiches are not as big as you would think. They are bigger than most deli-style sandwiches but not quite as colossal as I thought it would be. Also, the meal is served on a piece of wax paper... This is probably tradition but I think a plate would better suit. All in all, my experience was good at this tourist-flocking sandwich shop.