The program seems good - they have the standard 1 year of TA duties and classes, oral exams, ect. I'm curious if I can transfer my 6 grad classes from undergrad to bypass the class requirement, but I wouldn't mind taking them again...The only thing that seemed annoying were the cumulative exams at MIT, but the grad students told me not to worry about it. Also, while I personally don't like the idea of lab rotations, they don't make it mandatory, which I am very grateful for. I spoke to Movassaghi and he said I could start early (summer for certain, possibly next month, I still need to work out housing details), though I wouldn't be an "official" member until the same date as the other 1st year students.
Compared to other schools I applied to (like the Ivy leagues, though I still think they are great schools for our field), I thought MIT's student body was higher caliber (intelligence, focus, ect.) and more diverse. The campus is also really beautiful.
Buchwald sounds like a great choice!