> The schools that are so famous for their top-end research are achieving that research success by having those elite professors doing research, and that comes at the expense of teaching.

There's no guarantee that the less selective schools are any better at teaching. From what I've seen CMU and Stanford both had smaller class sizes and better teachers than RPI, but that was just from quick touring.

There are some schools with a strong focus on teaching (Harvey Mudd), but that seems to be unusual. I think in most cases if you get into a super selective school you should go if you can.