I am replying to your post as someone who is leaving gs to go into anesthesiology. My story starts in third year of med school when, after 1 week of my syrgery rotation, I had decided what I was going to do for the rest of my life. I loved the OR, I loved cutting and sewing, and I couldn't see myself doing anything esle in medicine that would make me as happy or be as fun. And like many students at other med schools, we did not have adequate exposure to anesthesiology until our fourth year. By that time I had already applied for surgery and was scheduling interviews. After my anesthesia rotation I began to question my decision.
So, anyway, I matched and started my internship. I hated it! There is so much more to the practice of gs that you don't think about as a student. I still love to operate, and I did a lot of that this year, but there is too much I don't like to justify my staying in surgery. For example, MANY surgerons/gs residents are not happy people, and some of them are even miserable people. Surgery is still, and probably always will be, a very egocentric specialty and I have a hard time dealing with people who are too full of themselves. Many surgerons practice CYA medicine because the current environment in medicine (esp surgery) is "patients vs. doctors" and it makes everybody hostile and on-edge. Many of my attendings are divorced and many of the residents don't have anything else in their lives other than work. One last thing is that the 80-hr work week, although they try to enforce it, rarely exists.
So although I still love the actual act of surgery, I cannot justify knowingly/willingly doing this to myself for longer than I have to.
Anesthesiology, on the other hand, is at the other end of the spectrum. Attendings/residents are generally much happier/nicer and are much more pleasant to work with. Not very many people have the God complex (that I have come across anyway). It's still a very hands-on specialty and I will still be in the OR, which I love. And the hours, in general, are better than gs which will allow me the time get back the things I used to do to that made me a human being (i.e. visiting my parents, playing the violin, working out, reading for pleasure, etc).
To me, this decision should be a no-brainer. But some people just love to operate so much that they are willing to put up with all the other stuff or they just don't think about it. And from personal experience, I really believe that by the end of a gs residency, many residents are not the same people that they were when they started, and that's sad. A job should never do that to someone.
Anyway, that's my personal experience. I am so glad I made the decision to switch and I can't wait to finally start my CA-1 year.
If you're really not sure, do as many rotations as you can in each field before you have to apply. And if you find that you made the wrong decision down the road, it's not the end of the world, you can always switch.
I hope this helps a little. Good luck.