The screen of a phone is almost always small for almost everything, even considering that you use the Galaxy Note. I did some quick size mockup of the Nexus 7 using an A4 paper (and guessing the screen size) and I find that its screen is just a little bit smaller than my SZS tankoubon. Which is sweet.... right up until the fact that the Nexus 7 isn't memory-expandable. Which is not sweet when you're planning to put anime and manga in there.
Apart from screen size, resolution is also important.
For example, I once tried to read manga on my laptop. Did not work, at all. It has the same resolution as my Note, but on the Note I can read in portrait mode instead of landscape.
The resolution was simply too low to properly read the fonts.