I vividly remember a student couple we knew who both stayed on the fast track and became doctors, through a very structured and rigid schedule with little time to pursue anything else. They came out the other end feeling as if they "had no idea how to be grown-up", as they put it. Granted, we all feel like that at some point, but at the time they were expected to take important decisions about other people's health and wellbeing, and felt totally out of their depth.

Nothing wrong with studying on through, but much to be said for broadening your experiences when possible. If I'd had the chance again I'd go for Peace Corps work, or something like it. I still dream about working for Medecins Sans Frontieres someday.