I know it's early days but I have been trying the Swype keyboard on my iPad with iOS 8 and have encountered some strange behaviour with Editorial.
It works very well for straightforward input. The problems come when I edit my document. Say I have a sentence "The cat sat on the mat" in the middle of a paragraph I want to edit. I want to change "sat" to "sits" so I put the cursor just before the "o" and hit backspace. Instead of just deleting the "t" at the end of "cat" the word changes into "cca" instead. If I keep deleting even weirder stuff happens, and words earlier in the sentence get mashed in too.
This hasn't happened in any other apps I have played with so far. I love Editorial so I thought I'd point these issues out because I imagine an ios 8 update will be in the works. Of course it could be a problem on the keyboard side instead.