I have the original iPad Mini. Just cracked the screen after 3 years of happy use. So will likely upgrade to Mini 4 (maybe Air 2). I use the Mini mostly for web browsing. (reading Newpapers, financial sites etc.) How do web page loading etc. compare between Mini 1 and Mini 4. My wife's iPad Air 1 seems much faster than my Mini. Will the mini 4 be a big improvement over Air 1?