Once you get in Harvard is not super competitive. It is extremely nurturing. The help at Harvard is unreal. Harvard is also much much better at the sciences than Yale. That is why Yale is spending millions of dollars to improve their science programs. Just look at CS 50 that Yale has had to borrow from Harvard. Also the average gpa at Harvard is about 3.7 while at a state school like Berkeley it is about 3.2. This can have an impact on your future. That is reason enough to choose Harvard over a state school