I've been to Mercurio's a few times, the food is good, not great. The pizzas are typically a smidge too blackened on the bottom, just enough to overpower the taste of the dish, but you can't go wrong with a salad.
The service is hit or miss. I've had exceptional waiters, but I've also had waiters that walk past enough times that your hair turns gray.
On a high note, ready for a pizza hack? Order the marinara pizza and a house salad, sans cheese. Take some salad, top pizza accordingly. It's fast, fresh, and only runs around $13 between the two.