For the benefit of those who may be considering BU for regular undergrad, let me clarify, it is no way grade deflated to be in the same league as the other 2 schools quoted, JHU and Cornell.
Most of the students on this forum should be able to notch up 3.75+ there except may be for SMEDs, certain engineering majors and business school. Those interested can search their website for the gpa ranges by major for latin honors which should give a fare idea. For SMEDs they try to keep the standards high not to let them slack a bit, but even then have known people getting 3.9+ amongst them.
The only other schools that I can think of to be in the same league as those mentioned by you are UChicago, Princeton, MIT and may be (or not) Columbia and WashU. Some of the UCs also fall in the category due to over abundance of asian origin students, ultra competition and not being as diverse as typical schools.