First off, OP, congrats on your acceptances - that's awesome.
Now, for my random internet opinion....
Here's sort of how I might break it down, off the top of my head:
MD
Pros:
-You get to be "the doctor," and all of the oohs and awes that may or may not accompany that status.
-You get to have the final say on your patient (in most cases) without worrying about someone signing off on your charts. You are, more or less, autonomous.
-Having a MD opens doors that would remain closed as a PA, e.g., as others have mentioned you have more of an opportunity to contribute to the field, if that's your thing.
-Regardless of what happens with healthcare, you will be paid more hour-for-hour than a PA (see below for further discussion of this).
-You have more say in pretty much everything. Where you work, how you work, when you work, what you do when your at work, what happens with the patients, etc.
-You get to be the "expert" in your field.
-Larger scope of practice.
Cons:
-Obviously, you will spend at least 11+ years of your life before you are really autonomous (4 undergrad + 4 medical school + 3 years minimum in residency).
-During that lengthy amount of time in training, your time is not your own and your family life may suffer, depending on how you choose to handle this reality.
-Lots of debt.
-Somewhat of a worrisome future with the changing healthcare landscape, but this isn't a dealbreaker if you know what you are getting into ahead of time.
-Unlike PAs, at least for the time being, you cannot just switch specialties "just because." If you are a board-certified practitioner of a particular specialty, you will have a hard time convincing anyone to take you into another residency program. It can be done, but it is not an "easy" process. Regarding the discussion above, all that I will say is that there are many "fields" of practice (i.e. subspecialties) within a particular specialty (i.e. IM), but switching subspecialties DOES NOT equal switching specialties. The former involves fellowships or on-the-job training; the latter involves residencies. Two different beasts. Is it "technical verbiage"? Perhaps. Nevertheless, if we are going to debate things, we must debate using terms that mean the same thing, lest our arguments be, in actuality, over nothing at all. /rant.
PA
Pros:
-Less time in school = more time to make money, practice, etc.
-The educational process is bit less life-consuming, leading to (hopefully) more time with family or to spend on outside interests.
-You can, at least for the time being, switch actual specialties (i.e. spend some time in the ED, then move to surgery, then to derm). This may, as has been discussed above, become a bit more complicated in the future, but will nevertheless pretty much always be easier than starting an entirely new residency.
-You can make good money.
-The changes in healthcare will more than likely lead to an increased demand for midlevel providers = job security for you.
Cons:
-You will always be "under" someone and never completely autonomous.
-Perceived lack of prestige from some physicians and perhaps even your patients
-You are not a doctor.
-You will make good money, but less money than a physician would.
-Smaller scope of practice.
One thing to keep in mind as you make your decision is the changing face of healthcare. Basically, everyone now, or shortly will, have some type of insurance, FWIW. That said, the basic infrastructure (available funds, available practitioners, facilities, other resources) will pretty much remain the same or decrease. In other words, insurance for everyone is awesome, but now more people will try to be seen by the same number of providers. Since the lion's share of the new insurance will be provided through governmental programs, this means that there is more or less the same amount of money available to fund these new "insured" individuals as there is now, which means lower reimbursements for providers. This will translate into a decrease in pay for some of the more high-earning physicians - more or less pay will probably become more "equalized" among specialties, without major outliers (as there are now). This will also mean that aging physicians will try to retire before the brunt of this all hits, and less physicians will be willing to work with those insured by governmental programs. For PAs, this means an increase in demand for their services, since they can do quite a bit of medical stuff for a significantly lower cost and practices nationwide will just need more bodies in general to shuttle patients through.
All speculation. Just things to keep in mind. For PAs, there will always be a demand that I would say will increase over the next few decades. You will get paid less, but you will be comfortable. You will not be a doctor, but you have to decide how important titles and scope of practice are to you. You will have more time outside of medicine to be with your family and do other things. For MDs, you will still always be paid at least a little more, and there will be demand. But the compensation you receive for investing your prime into education will be decreased significantly and the system will only become more difficult to work with.