Typing on the 5.7 inch screen is a joy. I was excited to use the stylus to type because I figured it would allow error free letter selection, and indeed it does. But it turns out the extra half an inch over my Galaxy S7 means that 2 thumb typing works really, really well. Very few errors and quite fast. So I end up never using the stylus for typing. A built in stylus would be more useful on a 5.0" screen. Anybody listening??
Interestingly it's almost possible to "touch type" on the Stylo, meaning without looking at the keys. This also reduces error rates because you can see errors as they happen and can be sure to select the proper word suggestions. I've never been able to do that on another phone, and I suspect it's the screen size combined with my greater experience with Gboard.
Swiping works fine too, but it's completely unnecessary, unlike with a smaller phone. I never thought I'd want a screen this big but I'm starting to come around.
The one area it works very poorly is one hand typing. The screen is just too big to reach across with one thumb. There are one-handed keyboards that stick the buttons in one corner, but I find it too much trouble to switch back and forth.