Upgraded my 5s yesterday, and just went back to 8.4.1. 9.0 definitely slowed the phone down. Scrolling less smooth, longer for apps to open. I waited too long to downgrade my old 4s from iOS 8 back to iOS 7, got stuck with 8, and that 4s was never the same, permanently losing its crisp, snappy...
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Courtesy of WestNet Wireless
www.westnet.ca