Doesn’t sound like this is a big component to your decision, but I would have guessed that the Claremont social scene is more dynamic than Brown’s. I think Brown has a lot more off-campus socializing/partying than Claremont, which can contribute to a more “cliquish” scene. When my Daughter and her friends visited Brown, there were no parties on campus that the hosts knew about, and the administration has gotten pretty strict about underage drinking at on campus parties recently. (from what I’ve read)
You can’t go wrong with this decision, but I doubt that a Pomona degree will disadvantage you over Brown, especially at a place like the NYT. Since you already have social and academic connections at Pomona/Claremont, my recommendation would be to stay there. And our family has a lot of (unrequited) love for Brown; I just think Pomona is an great school also and seems like an easier transition.
But it also sounds like this is your plan. If you eventually decided to go to Brown, would you do Fall semester at Pitzer? It could get a little awkward when you transfer your credits from both Pitzer and Pomona.