Having heard so much about these two places, I thought I'd try them both out. Given the hype over UPN (the ovens do this and this, the dough is such and such, the mozza is from where and where) I had higher expectations for it than I did Cronkites.
Now that I've been to both, I can say hands down Cronkites beats the pants off of UPN. Not only was the space cozier (UPN was halfway between a tapas bar and a minimalist chic destination), but the pizzas at Cronkites were infinitely superior. The DOC pizza had a thin crust, but not overwhelmingly so (none of that matzoh pizza that people somehow mistake for quality), with nice charred bits, perfect (perfect!) tomato sauce, and brilliantly made mozzarella. Their second and third generation pies are a little too complicated for their own good, and are worthless as a result. Stick to 1st gen DOC.
UPN on the other hand had a very billowy dough, with pleasant charring, but not much else going for it. Really that's the most I can say. It was entirely edible, and even enjoyable with a cold Peroni, but it was surprisingly bland. Ironic pizza, anyone? Not to mention, one individual pie is around $22. Cronkite I think was closer to 13 which left plenty of room on the tab for wine.