I think it depends on the hospital and its resources.
I work nights at a very small community hospital where there is only one inhouse physician (the ER Doctor) and very little "other" support. When I call the on call physician, chances are he/she doesn't know the patient. Add this to the fact that I work in a CCU/ICU and there is no REAL intensivist, and the "on call" physicians are GP's. When the SH_T hits the fan, I'm basically the one running the show until the ER doctor comes up to help . . . maybe.
I don't see how a new grad can receive the educational and clinical support that is deserved in a setting like this.
However, I used to work in a rather large teaching hospital. 24 hours a day there were all sorts of MD's, NP's, clinical nurse specialists just crawling up and down the wood work. Additionally, the preceptorship program was very strong and well organized on all three shifts (at least in the department I used to work for). A new grad working in a setting like this could do just fine.
Working nights. Guard your sleep. It's precious. I sleep in shifts, about 2 to 4 hours after I get home from work and then about another 2 hour just before going to work.
Hope this helps. Good luck with your decision.
P. S. My wife's name is Amy. It's a beautiful name!