Swiftkey sadly failed badly to learn from my swiping habits, inject the right auto-correct predictive text and continues to baffle me with insane word replacements I've never used. I've had it running on my iPhone for over 6 months now, praying it would get better as it's a nicer interface than Google's. But it never got better, smarter or quicker - just kept acting as if everyday was my first day with the product.
Oddly - Google did get smarter, better, faster and far more accurate over the same time frame. It seemingly took longer to catch up - but when it did, it crushed Swiftkey's capacity to predict my swiping - and now out performs 2 to 1 every day. I haven't necessarily given up on Swiftkey as I still use it for What'sApp - but for email and longer comms - I've switched over to Google Keyboard for good.