I can speak as a Princeton undergrad about some of the logistics of our relationship with PTS, if not how it affects doctoral work.
The town is safe and quiet, but spendy and impractical. One of the main reasons I didn't apply to PTS is that I want more life in the place I attend grad school. Many PhDs at the university complain about feeling trapped on campus without so much as a basic grocery story within safe walking/biking distance. (Princeton, NJ: home of 6 different ice cream shops, but no place to buy eggs and flour.) In short, it's not a place to be young and single - but I know some people at the seminary do fine with young families here.
Princeton and PTS have a pretty distant relationship, but access to a lot of each other's resources: libraries, class listings, etc. They're just so underused (at least on our end of things) as to be almost secret. I'm in the religion department and know more seminarians than most, and I couldn't give you all the details.