In Pittsburgh for business, and someone recommended Sienna Mercato. They compared their meatballs better than The Meatball Shop in NYC. I stand by my raving reviews of The Meatball Shop so I had to try it out and compare. I had two sliders- Classic Beef with marinara sauce and Vegetarian (mushroom, white bean, cauliflower) with spinach almond pesto.
Overall, the meatball sliders were ok. They were all about quantity than quality. Meatball was pretty big, but the taste was underwhelming. I'd go there again to try out their other items like the cured meats and pasta. They also have a beer garden on the rooftop. But I don't think I'd go get their meatballs again.