Like you I also came from the S3 to the N2. I had trouble at first getting used to the bigger size, but I'm 5'4'' with smaller hands as well. I found a way to make it work, though. Even with a CM Pop case on, it can fit in the back pocket of my jeans if I need somewhere to put it and I don't happen to have my purse or a jacket on me.
I like the phone overall and I wouldn't go back to my S3 even if I could (I've already sold it).
I can type better on it than I could on any other touch screen phone before this one (nothing beats one with a physical QWERTY keyboard, IMO however), just by using the S Pen and the Swype method.
The processing power versus the S3 is just... wow--switching between tasks is virtually flawless when comparing phones (and my N2 isn't even rooted yet).
The screen is gorgeous, but unlike some users, I'll be willing to sacrifice the crystal quality with a screen protector soon. That's no big deal to me as long as the screen isn't scratched to preserve resale value several months or even a year down the road. But for now, I love the quality of the movies on my N2. But the screen on my S3 was nice as well.
Using web-based apps and the browser also doesn't present with any problems for me. It's fast, I don't have to wait half a minute for pages or apps to load up on my home wifi or AT&T's network and I live in a rural area.
The battery life, without having rooted it, is acceptable to me. I can unplug my phone at 7 AM and use it off and on throughout the day with texting, surfing, phone calls, playing music, and start feeling uncomfortable with the battery level about 12 or so hours later.
The build quality is also impressive. I bent over to pick something up off my wood floor when I first got the phone and it slipped out of my sweater pocket, landing face down on the floor. No scratches whatsoever on the screen or bezel.
I am still learning a few things about the phone, running into some problems now and then that have to be fixed (a while back I came across a problem with the stock calendar syncing to my FB friends' birthdays on its own and my calendar looked like a nightmare, luckily someone on here helped me fix it). So it's still a learning experience even weeks later. This still would not make me go back to the S3, however.
But, I mean, if you're not comfortable with the N2 then don't keep it. There is no sense in keeping a device if you're not going to be happy with it. If I went out and got an iPhone tonight, I'm telling you right now I would miserable with it. Would I keep a phone I would be dissatisfied with? Of course not. I wouldn't expect someone else to, even after telling them the pros of the device. Do what you have to do, no one is going to change your mind once its made up.