I have a ton of friends from New Haven, and have tried Modern myself a few times. One of my friends likes Modern better than Pepe's/Sallys, but he is definitely in the minority. The nice thing about this place is that you usually don't have to wait like you do at the Wooster st. pizzerias. Modern is a little closer in style to Pepe's than Sally's, and is definitely a New Haven style pizza. I would say this is the place to go if you happen to be driving through New Haven on a weekend evening and don't want to wait around all night. Still a world class pizza for sure, but I choose to wait in line at Pepe's or Sally's if I have the time.
It is a LOT easier to get a pie at Pepe's than Sally's, unless it is the dead of winter or raining. Pepe's has two locations (right next to each other) the other being called The Spot, and both locations will answer their phone for takeout. The pizza tastes pretty much the same at both locations. Between The Spot and Pepe's there is just a much faster turnaround than what you get at Sally's. Sally's is really small just a few tables and booths, and REALLY slow to turn out pies. Last time I was there I waited an hour and a half for seating, then another hour for them to make the pie once we had placed our order. I went back to check out what was going on in the kitchen and they were moving in slow motion. As far as I can tell they will not even answer their phone for take out. I have heard that Sally's will answer their phone for about an hour each morning to accept reservations for that evening. They try to keep this a secret to service locals and regulars. It can really piss people off that have been waiting in line for two hours, and see a group of people walk right up and get seated. The pie, though, is worth the wait. I like the cheese better at Pepe's, but as a whole the Sally's pie is probably my favorite in New England. I like the softer dough and the sauce better at Sally's. The balance of the pie seems better at Sally's with just a slightly thicker crust (still thin crust, though) more sauce, and less cheese than Pepe's. The Pepe's cheese is really something special, though. If I could only figure out what they, and Vincent's in Pittsburgh are using my search would be over.