The engine is very good; it's recognized all my writing. The downside is that it is offline -- it happens in the cloud. This means it's a little delayed and sometimes it seems mysteriously unavailable completely.
Ha, I see your point. I used "offline" because it is happening in a way that is disconnected with my interactive usage. It doesn't analyze the handwriting as I write, it processes it in batch later, and this might even happen during a moment when I'm not connected to the internet. But I can see why this usage could be ambiguous or confusing.