While I can see some point in rankings, I realy don't understand b-school clusterings. Certainly, there are some criteria which distinguish Kellogg from Tuck, that's the reason why there is couple of positions in rankings between those two schools. But saying that Tuck and Kellogg are in different leagues is somehow immature and more like "BW style" posting.
What is my point? Well, there are greater differences between the schools within the same cluster than between the schools belonging to different clusters. For example, majority of the the members of this forum will agree that Stanford is >>> MIT, and they are in the same, ultra elite group. On the other hand, what is the difference between, say, MIT and Haas? MIT > Haas? Or MIT = Haas? Probably there is plenty valid arguments that could justufy one or another, but it is obvious that there is no such a large gap between MIT and Haas like between Stanford GSB and MIT. Certain applicant, lucky enough to get accepted both to Haas and MIT, would have to carefully determine pros and cons of each school and than make the choice based, most probably, on "fit" criteria and personal reasons.