I have just installed iOS 9 which seems pretty good however it contains a new feature, Ad blocking in safari. Safari on my iPad Air 2 and my iPhone 6 Plus are both pretty slow. pages take around 5 seconds minimum and 20 - 30 seconds maximum to load, even with iOS 9. Well after installing an ad Blocker which is a new feature in iOS 9, most pages load in under 1 second. I have a 200MB / sec internet connection so maybe you won't get quite the blistering speed I do however it seems significant improvements can be made to the speed of safari by blocking ads. To install an ad blocker. Go to the app store. search for ad blockers and download crystal. Crystal is the easiest and from reviews seems the most affective. There will be more available in the coming months but for now, this is doing the trick very nicely indeed. Once you have installed Crystal, you need to head over to settings - Safari - content blockers and enable crystal. Next time you launch safari get ready to be amazed. On my iPad especially I was blown away. Websites load as quickly as on my iMac 5K with 24GB Ram and a 4GHz processor. Literally instant instead of 5 - 20 seconds.
I hope this helps.