I'm IM, but my husband is FP, so I have a pretty good idea what is involved in both residencies.
Some questions you need to ask yourself:
1) Do I prefer a clinic based primary care practice or a hospital practice?
2) Do I want to treat a variety of conditions and a variety of patients or do I want to subspecialize in a narrower field with patients who are more homegenous?
3) Do I plan to practice in a small community (where you may be the only physician in many instances) or do I want to practice in a large city?
As for me, I plan to specialize, and it would drive me nutz if I had to constantly "switch gears" -- taking care of OB/Gyn, Pediatrics, Ortho stuff, etc. However, my husband would be bored to tears if he had to see a cardiac or nephrology or pulmonary patient over and over again. I feel that the family practice residents are a lot better prepared to go into a primary care/clinic practice than the internal medicine residents, and they get a lot more experience with clinic procedures/billing/running a clinic. However, I think that the Internal Medicine residents get more experience taking care of hospitalized patients. Plus internal medicine residents have so many options when it comes to subspecialty. So it's basically where your interests are!! Hope this helps 🙂