As another Loyola alum, I would agree that the school has a great basic science curriculum. I took a few labs in the new Life Sciences building, and the facilities are outstanding. I've had nothing but good experiences with the science professors there (including Kroll!), and I felt well-prepared for the MCAT with the basic science instruction I received.
I don't know much about Bradley, but the pre-health office at Loyola is fantastic. As you progress in your pre-med career, this will become more and more important since you'll be working with the pre-health office frequently during your junior and senior years. Make sure the school offers advising and guidance specifically tailored to pre-meds.
Also, Peoria is VERY different than Chicago, and Loyola is also in a fairly urban and diverse area. Make sure that you visit both schools before deciding between the two. Don't just take a tour of the campus, walk around and get a feel for the surrounding community.
$4K a year may sound like a lot, but ultimately it's nothing compared to finding a college that's a good fit for you. You may find ways to cover that difference during undergrad -- for example, I received free room, board, and a small stipend my Jr/Sr years for being an R.A. Loyola also has several grants/scholarships that they offer to current students who serve as campus leaders.
Some questions to ask:
-Does Bradley have a pre-health committee that can write a letter to med schools on your behalf?
-Do you prefer a big city feel, or do you feel better suited to the suburbs?
-If you end up abandoning pre-med (as a good number of students do), would you like the school enough to stay there?
Just a disclaimer: Because I loved it there, I am quite biased towards Loyola. I'm sure it's not for everyone, though. Just do your homework and you'll be fine. Best of luck!