This is by far and away the best app I have found for taking handwritten notes on an iPad Pro using the Apple Pencil. The Pencil is smooth and responsive, no lag, no offset. You can create multiple folders (categories), name your notebooks, import PDFs and highlight and annotate them in the app. In short it does everything I was looking for in a Notes app.
If it has any weakness at all it is in exporting options, since notebooks created in Good Notes and exported in Good Notes format are done so as a ZIP file. However, you have the option to export as PDF or image file (PNG if memory serves), as well.
All in all, this is the only app Im using for handwritten notes on my iPad Pro. I couldnt be happier with it.
Woody the Woodchuck about GoodNotes 4, v4.9.3