Arlen is a fictional town and First Aid is a fictional Step 1 and 2 study aid.
Sorry, I think First Aid is vastly overrated. It may have been good ten years ago when the Step tests were longer and trivia based (with discrete answers like e) Virchow's Triad) but the format of First Aid does not lend itself to the conceptual nature of the current tests.
In other words, you're going to waste your time learning discrete facts when most of the questions on the Step tests are of the "What is the next step in the treatment" or "Which set of lab values represents the patients condition" variety.
First Aid may be updated every year but if you look they also keep a lot of the previous years material. I think First Aid needs a major format revision, not just a periodic addition of small amounts of new trivia added to a pool of the same.
I just don't think reading First Aid or even the BRS books is going to help you that much. Put yer' friggin' flame throwers down. This is just my opinion.
Online questions like USMLEworld and Kaplan qbank are the most high-yield in my opinion. If you do all 2000 of each in preparation for Step 1 (reading the explanations to right and wrong answers, of course, I think you will be well prepared.