i just attended the info session at BU this week. the admissions officer clearly said there is a “big advantage” to applying early to BU. He said the mean ACT/SAT and GPA of those accepted through ED are lower than those accepted through RD. I thought this was a brutally honest and incredibly important info. He did, however, warn that ED is binding (which you already know) so you have to be prepared to commit regardless of the financial aid package they offer you. It’s a risk but if BU is your first choice, then you should definitely apply ED. I hope this helps.