Does anybody have any feedback on which is a better resource for the NBDE Part 1 (First Aid for the NBDE or the one for the USMLE)? I've heard that the First Aid for the USMLE is more thorough, and it has also been around longer so there aren't as many mistakes, etc. If anybody has looked at or used both in their preparation, can you please provide some insight? I'm trying to figure out which one to use. Thanks.