Despite having an Ipad Air, I use my PC more for games, internet, email, Office, consuming multimedia, editing multimedia, and general productivity. I've gotten annoyed by the freemium/free-to-play model for one iOS game, realized I can get a much better version for Steam. I do basic image editing on PC (which I'm sure isn't that bad, but I haven't gone through with this as of yet), and Office documents are a breeze on a desktop. Last but not least, I'm a hobbyist computer programmer, and it's REALLY nice having a real life keyboard, and 26" monitor.
I use the Air mostly to play a card game (Ascension), and I'll "pre load" web pages so I can view articles on the go (I don't have cellular model, and some places don't have wifi). Much nicer than on an Ipod Touch 5 (never mind the tiny screen, but the Safari pages often reload and won't be accessible without connection when this happens), and my 5" Galaxy s4.