Phew! This has been weighing on my mind for a few weeks (months) now, but DH and I toured one last center this morning, and made a decision after that tour. We've decided to go with the first place we visited, that came highly recommended by a colleague that I trust and love dearly. It's a little pricier than the others (by $185, so not a lot), but we just had a better feeling about it.
Another thing checked off the list!! Now, off to find a pediatrician, since the one we had picked (that came recommended by the same colleague above, a colleague of DH, and two other friends that live in our area) is not accepting new patients.