Well, now you've heard it from the horse's mouths, and contrary to aphorism, feel free to look in these horses' mouths, and even to count their teeth, because they're not selling you a load of bull. Claremont just isn't cut out to be a college town. There isn't anything to do except walk around and buy overpriced doo-dads, (e.g., the doo-dads your grandmother might find appealing—not to cast aspersions on your grandmother's taste), which will likely leave you unimpressed. LA is great, but only if you have a car. Public transit to LA just doesn't cut it for evening excursions. The Inland Empire (the area surrounding Claremont) is pretty trashy, and except for a few dive bars, doesn't have much to offer in the way of activities. Oh yeah. There is a flea market in the Inland Empire.
Claremont is far more of a retirement community than it is a college town; you will exhaust its entertainment potential in about a day. Los Angeles is a cultural mecca (well, at least a cultural hub) and boasts tons of museums (if you can, check out the Museum of Jurassic Technology), stores, beaches, clubs, and bars, and you'll have a difficult time running out of things to do there. The other colleges provide a nice break from Pomona, but aren't really different enough from Pomona to constitute an off-campus experience. Prepare to be absorbed by the giant social black hole that is Pomona College.