I know the 13" comes with 8GB of ram, but I really prefer the smaller form factor. I'd plan to use it as my main PC for the next 4 years and hopefully sell it for $250 Canadian in 2020. I'm seeing 2011 Airs go for over $600 now, so I think that is pretty reasonable. Basically looking to budget around $200 CDN per year of use. My main questions is how do you people think it will hold up for the next 4 years (basically for Sierra and the next 3 OS updates). Do you think the 4GB of ram could make it unusable at that time? My personal needs are very minor. Just web surfing, watching videos, using Microsoft Office, etc. Nothing demanding at all. Thanks!