Generally, this is a harbinger of bad things to come: very few great dough-slingers feel the need to hide their crusts under a thick blanket of melted mozzarella. But at Sal's, this is not the case. The crust is classic New York. Thin, but not absurdly so, with a nice crisp, floury char on the bottom and a thin layer of tender, doughiness right underneath the sauce.
The sauce is balanced and not overly sweet, and the whole thing is well-seasoned. Indeed, if Sal used a lighter hand with the cheese, this may be pretty close to perfect New York slice. As it is, it's a great filler-upper.
I didn't try any of the mini, single-serving pizzas they had ($6 each), but they seemed like a better deal, in terms of pizza-per-dollar, than the rather expensive $3 slices.