The reason I keep the spelling helpers switched on is that I mainly use my iPad mini for writing tasks. Because of it's smaller form factor I'm able to type using two thumbs (Blackberry style) at approx 50 WPM without the need of an external keyboard when using the device in portrait mode. I can write for long periods without fatigue (in just about any situation - standing, sitting, in transit etc.) and the auto-correct picks up the vast majority of my clumsy 'fat-thumb' errors. However there's always a smattering of British/US English auto-corrections that interrupt my flow.
It makes me wonder how Editorial behaves when using non English languages.
I use Editorial for writing tasks (mainly markdown) because the workflow system provides such a wonderful way of manipulating text or communicating with other apt IOS apps such as Terminology, Phraseology and TextTool. I have other IOS text editors that I use for 'productivity' or programming tasks and with these I always switch off the spell check mechanism but editorial hits all the right buttons for me as a writer's tool. Even if I need to insert web links or such like I can keep the readability of my writing by easily inserting them as reference links through simple workflows.
Although Editorial is a geek's paradise it's also to my mind by far the most useful writers tool available on IOS. However it needs to continue to answer the needs of both audiences equally - it is after all named Editorial, not Textastic or something similar.