So I have an Iphone 6 that is still running ios 8.1.2 It's been working like a dream for the last 4 years, not a single problem the entire time. Now, snapchat logged me out and won't let me log back in citing "connection problem". I guess they're just forcing me to update. I've heard the horror stories about phones slowing down, shall I update to the latest ios? Is there any chance at all my phone will perform the same?