Same here: waiting for reviews before I jump on the wagon. Although, my primary motivation is to read PDF documents, especially the 2-column ones, than the prospect of taking notes or drawing. I hope it won't disappoint.
This is a kindle for you, so why would this be different?
I believe Sony and Fujitsu sell a 13.3" epaper device and of course the iPad is available in that size. There's a whole lot of space between the very limited $700 Quaderno and the super powerful $2000 iPad Pro.