I was considering buying a new iPad to replace my 2013 Air that is starting to show age surfing websites. According to: https://en.wikipedia.org/wiki/IPad the only difference between 5 years of development is the CPU, RAM size, and megapixels...and of course exactly how new of an iOS can be installed. Are there other differences such as better speakers or longer battery life? The physical dimensions are 99.9% the same. I was hoping for major leaps in screen resolution or battery life or significantly better Facetime camera (1.2MP is a joke while my 2+ year old iPhone 7 is 7MP) or stereo/better sound after 5 years. Thanks in advance!