I am not sure if I have my info correct, but BU allows you to take medical school courses and Loyola allows you to take graduate courses. BU can be completed in a year if you select the library thesis route. If this is true, I'd select BU over Loyola since success in graduate courses proves you can do well in graduate school. Success with medical school courses proves you can handle medical school.
guaranteed interview.. its for the year after you graduate, so there would still be the lag year
Newer program: i think only a couple classes have graduated, while BU has been around 15 years
Easier: not to say that it will be easy overall, but from what i've heard BU tends to be much more rigorous
Supporting Staff: both seem to have good support systems in terms of profs and advisors