I am typing this from a mid 2011 MacBook Air 1.8 i7 4gb ram 13inch. It has served me well. I have only had to replace the fan when after 5 years it failed. I have been happy with it but its time to upgrade. I am stuck between maxed 13 MacBook pro or the 2.9 15 MacBook pro I currently use my MacBook air for school (MS Office), Web browsing, etc. With that said I will soon be entering into a pre med program where I may be needing a bit more power for things such as 3D anatomy programs. I can't seem to find a good size comparison image between a 13" MacBook air and a 15" MacBook pro. I don't mind the extra pound of weight of the 15 inch as long as there will be a large increase in power. I would prefer a larger screen as my eyes just aren't as good as they used to be. This laptop will be with me for 6 years (Until I finish Medical School in 2023) It will eventually be supplemented by an iPad Pro in 2021 when I begin clinical rotations. Should I go with the 15" or the 13"? Will either be a significant speed increase from my 2011 MacBook Air?