If this device existed and worked as advertised I would but one and use one.

If it is thin and light I would carry one everywhere - the way Kindles get carried around. I currently carry pads and paper everywhere.

However - I don't want features. I want a really good writing/sketching/doodling experience - something that an iPad cannot supply. The only feature I'd want is the ability to easily get my notes onto other devices

Why shouldn't we carry an iPad, a Kindle and a Notepad?