Has anyone had experience using both the i5 (preferably 256gb version) and i7 versions of the Surface Pro 3? I'm curious for some feedback on how you would compare the two (Perceived performance, I've seen the benchmark scores, but can you notice the difference in actual use? in what use cases?) (fan noise/heat) (battery life). Including any specific use cases in the comparison would be helpful. Most folks have experience with only one device or the other. And the professional reviewers seem to have only been given the i5. So it's difficult to find information on comparisons...I'm using an i7 and wrestling with the idea of downgrading to i5/256gb.