I think those 6 weeks are probably less special for me since I have spent a fair amount of time enjoying life. What I really don't want is to come home from a long day at the hospital during intern year and say "wow, I would really like to sit down with my girlfriend and my dog, perhaps have a bee.... oh wait I have to study broad swaths of medicine that aren't specialty related." I think my life would be less stressful without step three looming. Just a thought. If I'm going to fail step three if I take it too early, then sure... but if I am able to pass step three at the end of fourth year I am inclined to take it.