The iCloud integration is, as with most other apps, painless and quick. I’ve found that apps which sync their documents through iCloud are quicker and more reliable. However, what I don’t like about using iCloud syncing is that it is application-specific. And so, in a way, an app becomes a silo of my work.
I’m trying out Byword for writing blog posts, and so far this is my main sticking point. Keeping all of my drafts in Byword means apps like BBEdit (on OS X), or Elements and Writing Kit (App Store) (on iOS) into a secondary position. Each of these apps does some — or many — things better than Byword, but if I choose to use iCloud, a multi-app workflow will be a lot harder to maintain.
I have more to say about this, so I’ll save the rest of my thoughts for a more thoughtful review in the next day or two. I will say that I think the Metaclassy folks did a great job on both versions of Byword and most of my reservations have been about iCloud syncing as a concept, rather than Byword itself.