virtually anywhere* (so basically many schools, no matter how good they claim to be will have a couple of biology instructors who are not up on modern teaching and testing methods and it will look like a glorified high school course, maybe not even AP/IB level thinking, but with extra content). And when I say not rigorous, I mean they are often not rigorous in the “correct” way.
As for “culture”, one is a small town in suburban metro Atlanta (SE suburbs) and one is Atlanta"ish" (it will likely be annexed into Atlanta proper). It seems Oxford attracts a lot of the same types at main (like I said, lots of overlap in career goals), but with some more quirky and intellectual types (these may be those who didn’t apply to main or did, but outside of main applied mostly to LAC like schools or much smaller universities and colleges) and ethnic, and geographic demographics support this. The evidence that they may attract a more concentrated amount of intellectual types on top of the pre-professionals that main often attracts is the fact that Oxford seems to send a higher proportion to graduate school programs (not professional, but like MS and PhD). So they get many more of the “I not only like this subject as a major, but will pursue it as a career” types whereas main seems a lot more like: “This major is common to those pursuing this somewhat related career path”. The differences are lesser so from location I bet and more so from a difference in size and mission.