You can make a good living doing it and not killing yourself. As VA noted, you need to be efficient billing. Medicare provides a lot of opportunities there. Some advantage plans you can bill 3 codes per visit with medicare wellness, regular preventive code and problem based e&m if they come in with something (99% of the time they will). Its pretty easy to document in most patients level 4s regardless of what brings them in. Also you can't be afraid to bill level 5 when the visit is cumbersome and takes up a lot of time and decision making.
I will say that I think its really hard to do a top notch/comprehensive job as a PCP if you're seeing more than 20 a day. Many jobs will push you to do this and the money itself will push physicians to want to do this. Anyone who says they can see 30 plus patients a day and do a great job is probably not doing as great as they think they are (unless a big majority of your patients are urgent care type visits). That's why I think its so important to bill efficiently.
I'd also argue that although IM isn't your bread and butter trained outpatient medicine, where we lack in some of the basic MSK/gyn/procedure/derm etc, we are equipped to do a much better job of juggling DM, HTN, CAD, CHF, CKD etc in an outpatient setting. This is where I see a lot of patient's who have been seeing family medicine for some time not getting standard of care. I feel like a lot of patients that develop a lot of chronic issues as they age benefit from switching over to an internist. Not to say a lot of FM docs don't do a good job with that, but each specialty is going to have its strengths and weaknesses.
