Turns out it makes some pretty decent slices. Someone online called it the best slice in the West Midtown, which seems reasonable to me. There was a Manhattan pizza blogger named the Slice Harvester who really liked the place. Of course the pizzeria has really been publicizing that, as well as some of their other good reviews.
I went back and had one slice each of their regular cheese pizza, their white (all cheese, no tomato) pizza, and the upside-down pizza (tomato sauce over cheese on top of a sicilian thick crust).
Summary: It's still pretty good pizza, better when the place is busy at lunchtime because then the pizza is fresh and not reheated. My preference is still for their regular cheese slice, which is a fine representative of the New York thin crust pizza variety. Regular slices are $3. Specialty pizza slices start at $3.75.
Not a destination pizza, but if you're at Penn Station this is a much better option than the places inside the station, as well as many of those in the neighborhood.