What do you find lacking in iOS’s swipe keyboard implementation?

Poor word choices. Backwards "corrections" that are incorrect.

I can't comment knowledgeably. I just regularly have to try over and over again to get it to produce the word I want, and my memory is that this happened rarely on Android.

Wait! I do have a specific criticism!

There are certain two-word sequences it will not produce ("kill myself", "white women") and I could do without that little bit of editorial oversight thank you very much.