How often do you upgrade?
I upgrade when there's New Technology. Period. Or scratch that New Innovation. How ?
IPad 1 was just a big iPhone I purchased the 4th Generation iPad Why because.
IPad Gen 1 was just a big iPhone
Gen 2 don't Remeber
Gen 3 Had Retina Display but the same A5 CPU as the Gen 2 so historically the worst iPad
Gen 4 (my baby) Had Lightning cable and a new A6X CPU and Retina Display this was November 2012
Gen 5 Air 1 I was so mad.
Gen 6 iPad Air 2, my Gen 4 was dropped or damaged at the Apple Store worse than it went in. Manager had no units on hand and Upgraded me to a Air 2 on the Spot October 2014. It was like winning the lottery still Remeber what I wore, what I ate that day. A Stale bagel tasted liked roast beef I was so happy.
2015 we won't talk about the year Apple forgot.
2016 March 31 Got a new iPad Pro 9.7 LTE sold my Air 2 for $300 cash right before the new 9.7 Launched
2017, Who Cares the 9.7 Pro crushes everything still No Major updates Expected that matter.
2018, Intel Powered iPad Pros with Smart Connector 2 and some type of Touch Bar Smart Keyboard And Run Mac OS. And 1 USB-C Port. To charge do everything. Maybe OLED displays and new body design.
Starting with Gen 4 I am on a Tic-toc pattern. Apple makes big leaps every two years.