I considered PA for some time, and now I'm set on medical school.
I think that many people assume that since PA means "physician assistant", the PA basically does what the physician tells them what to do, and does basic tasks. This generally is not true.
Yes, a Physician Assistant is a medical professional that is licensed to practice medicine with the supervision of a physician. What "supervision" means depends on the state, as well as the "supervising physician". This may mean that the physician sees the patient with the PA, that the physician signs off on all charts, that the physician signs off on only a few charts a month, etc. Typically, the MD/DO does not have to be physically present with the PA. In surgery, the PA will typically be the First Assistant. The PA may then follow up with the patient post-op.
PAs can do histories and physical exams, they can diagnose, they can perform various treatments and procedures, write orders, and they can prescribe medications. Again, the scope of practice of the PA is dependent on the state and the supervising physician. I work in a hospital, and when I'm bored, I read the protocols and procedures of some of the departments (yes, very nerdy). For the PAs in the Emergency Department, for example, they can see and treat to discharge the basic cases, without the physician seeing the patient (though the MD/DO has to sign off on the chart within 24 hours). With the more complex cases, the PA must present the patient to the attending before discharge. Again, this depends on the state, facility, and supervising physician.
Most PA programs are 2-3 year Masters programs. Some are still bachelors (though of course the material is at the same level). The first year includes didactic education, while the second year includes the clinical rotations. PAs then have to pass the certification exam, the PANCE (Physician Assistant National Certifying Exam). PAs also have optional 1 year residencies in certain specialties. Lake Erie DO school just announced a PA-DO bridge program, which takes out basically 1 year of med school (if I remember correctly).
Why did I stop thinking about pursuing PA school in favor of medical school? Because I didn't want to wonder "what if?" later on. I like that PAs are able to switch specialties without going through a residency, however I think that such an option may not be used by myself. While the level of autonomy of a PA can be good, depending on where you work and your SP, you will always have to have a supervising physician. In some ways, its like if you're a resident for your career.
than 
