Former philosophy major here. I’ll do my best to answer your questions.
In the PGR, you get the impression that Leiter might recommend smaller schools over bigger ones. The former might be more undergraduate focused but will likely have less prestigious faculty. I actually emailed Leiter to get some clarification on this issue. He emailed me back essentially saying it depends on your individual needs and what environment would work best for you. So striking a balance depending on your individual needs is recommended. I can’t make further recommendations without knowing what type of school environment you’d prefer.
A motivated student could get close interactions with faculty at a larger university just as they could at a smaller one. I certainly did. But if you’re not the type of student that can just go up to a professor and strike a conversation, or perhaps speak up in a large lecture, then that would not work for you. There are compromises by going to office hours however, which, in my experience were generally empty.
What are your long term goals? Do you want to go into academia? Law? Something else?
NYU has a great program. It is very prestigious for philosophy. Its faculty are certainly among the best in the nation. But that doesn’t necessarily mean that they’re getting into the best programs. I know of two NYU grads. One of whom got into a top twenty or so department; and another who got into a top ten department. I also knew of other graduates of very prestigious programs that didn’t do that great. One of my former professors who went to non-reputable graduate program got a job because he was a genius (or that’s what everyone said anyway.) Outside of that, I only saw jobs go to people from the top 1 – 2 departments.
If you’re a California resident, the UCs provide a great program. UCLA and Berkeley in particular are excellent. And USC now has a very good program as well.
And yes, Michigan does have a great and respectable philosophy department and has for some time. 