Thanks, I ended up going with the 10.5" one. It's the size of the steno pads I scribble on and weighs less than the bigger on. Not a lot of space on my desk either.
I'm gonna give Notes a try for a while and also Notability, because it appears I purchased it years ago.
The rumor for next year's model is that it will get face id and that's something I definitely want.
The one big downside to note taking with an iPad is that it turns itself off frequently. Having to authenticate frequently with the home button is a pain and I think face id would be a lot less intrusive.
FWIW, I still scribble on paper, but that tends to be for very ephemeral things (like a number I need to remember for the next 5 minutes).