[A2A] I went to a top 20 school, University of Minnesota for my Ph.D. So, my reference is that. I was a TA for a lot of students (~300) during my stay at UMN. I don't know about higher ranked schools, but, I would say that UMN is better than IITs only in infrastructure. The quality of teachers is comparable or better in IIT (at least IIT Delhi, EE). The intellectual capability of peers will definitely be better in IITs (I am talking about average, here). So, if I were to rank based on undergraduate education, it would be:
IIT (10 years back) > IIT (today) > UMN
Moreoever it is practically free to get an education in IIT compared to any university in US.
Narayan Murthy (the founder of Infosys) once said on a US documentary about IITs, "My son wanted to do computer engineering from IIT. He could not get in, so he went to Cornell."
PS: This does not mean IIT is better than Cornell. I don't know.