It wouldn't really replicate my multiple notebooks scattered precisely across my table, unless I had like 5 ipads. Also, not really a fan of Apple's mobile ux, so it's not the solution for me.

I have managed to get rid of some paper usage by having multiple dry erase boards of various sizes. One digital solution I have considered is something like the boogie board. If you're not familiar, it's basically a 10 inch digital whiteboard that can save the screen to an image and costs around $20. That's cheap enough I could have a pile of them and mostly replicate my current process.

iPad UX has changed a lot with iOS 11, I think you’d be surprised at how easily you can switch between notebooks on an iPad or have them side by side. One thing I would suggest is to go to the Apple Store, buy the 10.5” iPad Pro and try it out for 2 weeks with an app called Notability and then return it before 14 days is up if you dislike it. They have a great no-questions-asked return policy at the Apple store. If you end up liking it, you can look for a used model if the new one is too expensive for your tastes.

I think it’s a better long term solution than the boogie boards because it has handwriting recognition and it’s seamless + synced to the cloud without you doing anything. Also, the 120hz refresh rate on the new displays make it behave closer to the physical experience than on past displays where there was a short lag between your stroke and the stroke appearing on screen.

The boogie board is also a great solution if most of your notebooks are meant to be throwaway scratchpads. It might be a better solution than iPad if you don’t intend on keeping the stuff you sketch out. Plus it’s cheaper like you said.

All I’m saying is that it’s something worth trying out at the very least since you can try it with no cost. It’s been working very well for me.