I'm a senior academic internist who first certified 20 years ago, recertified 10 years ago, and just successfully recertified in April.
The exam has gone downhill. Maintenance of certification is an expensive and worthless waste of time that unfortunately many hospitals and clinics, including the academic medical center where I have a tertiary practice, require--except for those who are grandfathered, some of whom are actually younger and have less education than I do (because I was a graduate of an MSTP, just missing out on being grandfathered myself). Moreover, I personally know some of the individuals in senior roles in the ABIM and ACP; best that I bite my tongue. I will say that I am repulsed by the salaries they make for a largely ceremonial title and by the fact that some members of the board who are grandfathered have not themselves condescended to take the exam that they preside over. Talk about being a hypocrite.
I also am boarded in another specialty, not an IM subspecialty, for which MOC is similarly required. I am a little bit more impressed by the process there, but it still has issues.
All that said, let me tell you what has worked for me.
First time around, I felt that doing an IM residency was the best preparation. The exam seemed relevant and I actually enjoyed preparing for it and taking it. It was a rewarding experience. Back then, I primarily relied on MedStudy. I felt that the MedStudy review book was great back then. It was slim, concise, had none of the extra study materials it now offers, and was all authored by a single person. Consequently, it flowed from one subject to the next and covered everything without redundancy. I purchased MKSAP and found that it was way too long to read and, in retrospect, was largely irrelevant; I hardly touched it.
For the first recertification exam, I purchased MedStudy but was disappointed that it had ballooned in size, had extra material in addition to the main review, and was now a multi-authored volume. Consequently, I then purchased FrontRunners and found that to be more useful and largely relied on that. I read FrontRunners twice and did the questions, which, in all honesty, weren't very good or relevant. I also purchased a used copy of MKSAP and again found that it was too long and in hindsight even less relevant than before.
For the second recertification exam, I didn't bother with MedStudy or MKSAP and started off with FrontRunners. I was disappointed to see that FrontRunners had not been updated all that much and that some of the same typos and factual errors had persisted for 10 years. Moreover, I just did not have the patience nor time for studying this time around. (Based on my actual exam experience, I think I would have placed more emphasis on FrontRunners, if I had failed and had it do over again, for reasons I'll explain shortly.) So, I bought a bunch of other books off Amazon. I found Dr. Fischer's Kaplan review to be terrific. I cannot praise it highly enough. I also know one of the main authors of Board Basics, and he gave me a draft copy of most of the chapters to read. The other thing I found useful was the MedStudy flashcards, which I did purchase. I bought First Aid but didn't like it and didn't use it.
So here's how I prepared.
First of all, my clinical practice is esoteric and limited. I have been away from general IM for nearly two decades. On the other hand, even if I were a full time primary care internist I don't think it would help. 90% of the exam is on topics that I would not consider general internal medicine but rather ophthalmology, ob/gyn, pathology, surgery or some other specialty--possibly not even related to medicine at all. Of the remaining 10%, 8% are things you will never see--a few I had never even heard of and I savor esoterica--and the remaining 2% are things that you will see but would be committing malpractice if you did not refer to a subspecialist.
For the most recent exam, I spent about 2 hours a night for the 2 months prior to the exam with a bit more time on weekends. (This was probably about a third of the amount of studying time I did for the previous two times. I honestly didn't really care that much if I passed or not.) I read the Kaplan review twice and did about 2/3rds of the questions in the accompanying question book. I read the chapters that I had for Board Basics twice. I read through the MedStudy flashcards. I read the first few chapters of FrontRunners and did the accompanying questions. I passed. Scores have not yet been provided.
My impression of FrontRunners this time around before taking the boards was that it had too much foundational material; the author had made an attempt to give simplified explanations of the basic science behind the problem. From my prior ABIM experience, I did not think that was relevant. However, the exam has changed. There were a lot of short questions that seemed to emphasize first year medical school sort of knowledge. For that reason, if I were to do it over again, I might include FrontRunners in my preparation. At $500, though, it is just way too expensive, in my opinion.
Board Basics was pretty good. Perhaps the final published version is better and more complete. I did not want to purchase MKSAP and I could not find any used copies of Board Basics. There was no way I was going to give $700 or whatever to the ACP to get it. As far as I know, the authors of Board Basics are grandfathered and have not recertified. I respect the fact that the authors of both FrontRunners and the Kaplan review have done so. On the other hand, I suspect that some of the authors of Board Basics may be writing the questions on the exam.
The Kaplan review is fantastic. It is worth reading regardless of its value in board preparation.
The MedStudy flashcards are also relevant, perhaps the most relevant of all the study materials I used. They're relatively fun and quick.
This post is partly self-serving. I spent about a thousand bucks on all this material and now have it listed on eBay. You can pick it up for a fraction of my cost. Please take it off my hands. Thanks for reading. Good luck.