First, as of Labor Day 2012, they were cash-only at the ice cream counter, no credit cards. I note other reviewers here sometimes say cash only, some say credit cards accepted, but since the pizza and ice cream counters are separate they may have different options.
On to the food. Priced right to get the family filled on hot, NY pizza, by the slice or whole pies. Menu is broad enough to satisfy everyone, pasta, subs, and burgers. Separate ice cream counter with both regular and soft-serve, big banana splits and sundaes. Service - it's a counter place, so as long as someone takes your order and gives you food, there's not much to say about it.
Worthwhile to feed a big group, but there are plenty of other pizzerias nearby, just as good or better. No idea how it got such a high ranking, it's really nothing special.
If you own or manage North End Pizza, register now for free tools to enhance your listing, attract new reviews, and respond to reviewers.