Unless you do professional video, audio, music, picture editing - or are a serious gamer - then a M5 Air is serious overkill for most users. For that matter, so is the M4, but it has the added benefit of the recent drop in price at retail and via Apple's own Refurb site. May be able to get a higher spec'd M4 for less than its original price for base model - so still cheaper than the M5 base.