I'll respond with a more full answer after my IM shelf Friday, but for now, the main thing that I like as far as lifestyle is the sheer variety of options. It's easy to find jobs where you work really hard and make more money, but it's also easy to find jobs with fewer hours that still pay well. A few other things I like:
1. A lot less non-medical nonsense than other fields. Anesthesiologists don't have to waste time writing their daily note for 15 patients a day. They pre-op patients before surgery, run the case, get the patient through the recovery room, and then that's it. No coming around for the next 2 weeks to follow up and manage chest tubes or medication changes. You get a patient through surgery and recovery and you're done with them.
2. On a similar note, when you're done working, you're done. You're not like a surgeon, who may be at home and not even on call at the time but suddenly something bad happens with one of your patients and you need to come in. You're not an Ob-gyn, who has to worry at any given moment that one of your patients might go into labor and you need to come deliver their baby, so you're essentially on call all the time. You're not an internist, who has a list with tons of patients and comes in every day having to manage all kinds of new developments. An anesthesiologist pre-ops a patient, gets them through the procedure and out of the PACU, and that's it. It's one of the very few fields where, when you're off duty, you are actually 100% off duty.