One thing I would like to point out is that with these swipe keyboards I wonder if there could be a better key layout than the standard layout which was designed for typewriters so that mechanical keys won't get jammed and not for smooth swiping on a virtual keyboard
What you want is
Dvorak. The problem with Dvorak though, is that we all learned to type on QWERTY, so retraining yourself will be hard. But you can do it and some soft keyboards support it. And the problem with using
trace typing on a new keyboard is that your finger covers a significant portion of the keyboard display, so it's harder to know where to go.
That being said, I'm a new iOS user (2 weeks), and I immediately went to SwiftKey, because it was free and the stock iOS keyboard doesn't allow trace typing. It was okay, but when WordFlow came out, I kicked SK to the curb. It's a great keyboard for being new. I trace exclusively, so the arc mode didn't do much for me. I showed my wife and that was about it. I wish I could banish the icons for it since I'll never use it. It might help hunt and peck users, and 6/s Plus users, but on my little 6s, the regular mode is fine.
I want the Google Keyboard back... Heard a couple months ago they were porting it over, and they even hinted at some extra features. I remember the Android community (which I was a part of when I heard) was unhappy about that. I don't think they're wrong to think that Android should get the best of Google before us, but I'll be happy if we get it at all. WordFlow is pretty good, but the Google keyboard is much more mature software wise. For example, typing after a comma. SwiftKey doesn't care, will never input a space, even though there's always a space in English after a comma. Google Keyboard never will. WordFlow won't most of the time, but sometimes it will slip up.
Also, Google Keyboard got a huge update today. Sorry Apple fans — one thing Android is leaps and bounds ahead on is text selection. Like, I can tap somewhere in my text, and the cursor will just go there. If I miss, I can tap again and get it. It won't fight me on it. You know how in iOS it just wants to go to the end and offer to select all? Anyway, the new Google Keyboard lets you slide left and right on the space bar to move the cursor. So that's one iOS limitation that the Google Keyboard can prevent or at least reduce. Another feature SK and WF don't have (but I think Swype does) is the quick trace. Trace from the symbol key and the letters become symbols. Trace from the shift/caps key and they capitalize. So like if you want to say DVD, you trace from shift to D, shift to V, shift to D. Or parenthesis, you trace to I think K for ( and L for ), and you never actually leave the letters.
Anyway, in all my years with soft keyboards, I've learned decent ones are a dime a dozen. But one that just gets everything right... that's less common. I think Swype is near that point, but Swype isn't free, for one. It's a dollar, and the themes are $1-3 each. So it's not terrible. But it does keep a lot of freeloaders out, and on keyboards like SwiftKey and WordFlow, and Google's on Android. And they've done stupid stuff over the years, like wipe everyone's dictionaries (yes, this happened), and remove a feature a lot of people love. Trace right to left over Backspace to take out the whole word (Google just added this). And on their forum, they made it pretty clear that they didn't care what paid users thought, without explaining the decisions. So I would prefer to avoid them.