I have three handwriting apps on my phone, listed in order of usability:
1. Stylus Beta: write out what you want, then it has decent tools for going back and editing what you wrote. Good handwriting recognition. Same "linear" format as Google writing.
2. Samsung's s-pen handwriting recognition. Recognition is not quite as good. Editing tools are clumsier and harder to use. But going fullscreen starts to feel natural and you can see all of what you have written in context, so that's a big plus. In addition, it doesn't have to be your "default" keyboard, you can just pull it up when you feel like writing, and not pull it up when you don't.
3. Google writing. Obviously early beta. Almost no correction capability. Impossible to review what you've written in a meaningful way. I predict they will buy Stylus Beta and make it the new Google writing very soon, as they did with the photograph translator app that got integrated into Google Translate. They're just writing their own clumsy clone for now to see if it's worth buying.