Frankly, I disagree with this. I think everyone will have different opinions on this, so take mine for what it's worth... I do not think you should select an undergraduate institution based on whether you think you'll have an easier time there or not. You should pick a school that will challenge you, push you, and ultimately mold you into the kind of candidate that medical schools will salivate over. For me, that was my state's public school. With the research opportunities, over-abundance of campus extra-curricular opportunities, challenging science coursework, and tremendous professors/mentors, I decided that it was absolutely the right fit for me. I could have gone to an "easier school," but I also could have gone to a "harder school." But I thought that this one would provide me with the most impetus to evolve, both as a student and as an individual. I suggest you pick a school based on similar criteria, not percentage/distribution of 4.0's.