hi
its a good question.
everybody's situation / usage is different so there is a lot of discussion about this.
i have owned every MacBook Air model (except for minor speed bumps).
apple really does a great job at finding a balance between smoothness/brightness of display/battery life/price in every MBA revision.
this balance means that although its good for many (most i think) average laptop users, it also means its definitely not the best machine for people who have higher performance needs (gamers/video editors).
to be clear: i think both the i3 or i5 can last a very long time. more than 4 years to be sure.
but what i have said in my earlier post that you should buy an i5 for longevity is that we do not know what each major macOS revision will push each older machine to simply no longer being quite as smooth or quick.
we do know that apple will often not support macs older than 7 or 8 years with newest macOS. this is history.
its not just about having the latest OS, it mainly becomes an issue of security updates and compatibility.
but, for the final years of yr mac, after the initial 4 years, the question becomes for the last 2 or 3 years will yr mac be a source of pleasure for you to work on, or will it really feel its age and be slow and always be reminding you that you want a new mac. and, if you want to sell it in its 5th year, is it worth a price that provides a good downpayment for a new machine or not. or if you give it to a family member does it still have some useful value.
especially for the Air, since it is designed to not be a speed demon out of the box, getting it with 16MB is recommended (also a heavily contested point).
getting an i5 means there is no compromise at all, and (if past is prolog) definitely will be able to a great machine 5 or even 6 years from now.
sorry to reply to this post again but how likely do you guys think it is that a base i3 MBA with regular iOS updates will actually become annoyingly slow with simple tasks like word, Netflix etc in just 5 years? I understand that computers don’t actually slow down themselves but software updates and apps will become more resource intensive over time etc but how much of a difference do you guys think I would actually notice with my office and Netflix? If it’s just a few extra seconds to open up word then that’s not too much of an issue