Ania, young son should aim for top national research universities since he is very bright.
Well...I think this really depends on the personality of the student, the setting of the college/university, and how the interests of the student line up with the opportunities offered by the school.
Someone who wants a highly specialized arts major or an unusual dual major of some sort might do better at a small liberal-arts college that offers more personal attention, opportunities for internships and travel, etc. Sometimes the smaller schools even team up with a large research school so they can offer the best of both worlds: great humanities and great sciences.
I attended both a large research institution and a small, private, liberal-arts shool. Both came with pros and cons. But I know that I didn't have to work nearly as hard to get exciting, off-beat educational opportunities at the liberal-arts school as I did at the big research school. I was more of a number at the big school and I was a person at the smaller school.
I'm not trying to bash large research institutions. I'm just saying that I don't agree with the blanket statement that very bright kids should necessarily attend large research-focused universities.