The most important factor should be the school. More specifically, you need to think about the preceptorships. If the school you choose finds your preceptors for you, then relax (sort of - it's still grad school). On the other hand, if your school only "helps" you find preceptorships, then you need to think about availability. Boston, for example, has a huge medical community, but that medical community has led to a HUGE number of NP students looking for preceptorships. If you don't know anyone, finding preceptors can be difficult. It's something to think about, because the last thing you want is to delay graduation due to a lack of preceptor hours.