In my opinion, this keyboard has always been the best in the business. And I'm not saying that in a fanboy-ish way, especially given all the phones I've tried. That being said, I think it's particularly good for a fast, tap typer - because the auto correct is as good as it gets.
What it's lacking, swyping, is great for when you're confined to one-handed use or the autocorrect isn't very accurate. The latter is sometimes true for android, which is why it's great that it has swype on most of the popular keyboards. Next-word prediction also isn't very good on iOS; that's never been useful to me though due to how quickly I like to type.