I apologize if I've misunderstood your attitude. That's just how it comes across. I've seen you write almost exactly the same thing at least 3 times in the past few days.
I think it just depends on the person and how you are being taught at school. Some schools are stronger on board prep than others. During M1 I was mostly concerned with keeping my head above water, and definitely not doing board prep (but I was using review books in some topics, to help me learn). Summer between M1 and M2, I am reviewing 1st year and starting on 2nd year material, using board prep materials. Mostly it's review, to keep my brain fresh, but I'm actually really glad I'm using the board prep stuff because I've realized that while we have been very well prepared in most subjects, our histology was woefully inadequate. Now I know I need to really go back and learn the histo better while doing path next year.
Anyway, that's my take on it--study for classes, but be aware of which ones aren't doing a good job of preparing you for boards, and potentially supplement in the summer or over breaks.
Oh and it might also depend on whether your school has grades or P/F. Mine is H/P/F and I'm not in the top of the class (probably about average or just above average). I am more concerned with learning what will be really useful long term, including for boards, than with acing tests. But I'm also not gunning for AOA.