Actually, the information posted by Mr. Smith is misleading. PAs do require a supervising physician but that supervision is not direct. The physician doesn't even have to be present. PAs can own their own practice and simply hire a physician to review charts periodically.
PAs are not narrowly focused. They work in almost every medical specialty and have the ability to move between specialties. NP training is specialty specific so moving between specialties is more difficult for them.
NPs are only independent practitioners in states that allow this. Even then, independent practice requires a DNP degree. Many current NPs have an MSN. The vast majority of PA programs result in masters level degrees, which is the same level of education as a MSN trained NP. PA school is invariably two to three years in length with no breaks in the summer. 24 to 30 months is the normal program length. Much like medical school, PA programs involves classroom instruction and gross anatomy labs as well as clinical skills practice. Second year PAs go on rotations through various medical specialties for 12 to 15 months.
Most PA programs discourage working at all for the duration of the program, unlike NPs who often receive much of their didactic instruction online and are able to work at least part time during their program. PAs and NPs do very similar jobs in practice. They are both midlevel practitioners and both are good careers. The pay difference is largely due to the PA's utilization in surgical settings, particularly orthopedics.
Hope this clears up any misconceptions!