ScandaLeX
Wasn't Me
Your first paragraph I had no idea which phone you actually have until I got to the second....Which is better is truly a subjective opinion. While not much smaller, the GS4 is small enough that I find it more attractive for my usage. But there is still so much for me to learn about the GN2. I really wish there was more than 14 days to trial a new phone.
I don't know that I will ever use the stylus. I've never used them enough to develop the "need". But the battery life is refreshing. And I've read the phone and speaker on the GS4 is inferior to the N2.
So the question in my mind is will I have more utility (comfortably) with a smaller form factor? If so, at what price (loss of features)? At my present level of knowledge, I see no downside to moving to the GS4 if battery life is reasonable. I acknowledge that ignorance is bliss.
This can be such an individual thing. Seems like I could just flip a coin.

Many people who around these forums thought they'd never use their S Pen either; until they did--now they cant put it down. The S Pen is more than your average rubber tipped stylus. There are nice gestures you can do with just the push of the button that resides on it.
As far as size, the Note 2 is 5.5" and the S4 is 5".....that's not a huge difference and there's nothing the S4 does that the Note 2 cant or won't be able to do once Samsung upgrades it with the S4 extras.
Battery life alone is one reason if I were you I'd keep the Note 2.

And for the record, I find color reproduction better on Note II, although S4's excellent when it comes to daylight visibility.