Well, the decision probably could be made pretty quickly, but I spent about two hours each reading up about their biomedical sciences programs, and the projects currently offered by NIH through these schools. NIH itself is a huge pull, I have done internships at one of their primate research centers, and find that research just works much better with adequate funding. This program, aside from being cool, also guarantees that you and your advisor won't spend your entire time attempting to get grants funded, which makes the whole process that much better. So no, it wasn't just a spastic decision made on the spur of the moment.