Yeah I was thinking the same thing - why not just get the smaller version but after some thought thinking about my iphone experience, I am opting to go with the higher gb version just to be safe:
1). I download some apps that take up massive amounts of data - ie, gogo mobile navigator which is a Korea turn by turn GPS navigator. It actually installs the entire map database locally so you can use it regardless of service. The database is 2.5 gigabytes. I also have the Garmin US one which also has a large database. That's like 5 GBs right there.
2). I also download some big games that are 1-2 GB.
3). I Take a lot of photos.
4). I load a lot of movies and Korean dramas onto my phone - you laugh about the movies which are 1-2 gb, but the dramas are 20-30 episodes long and can total 20-30 GBs in aggregate! Yeah I don't need to have all of them on there, but I'm lazy! And I could convert them to a lower rez to match the note an have smaller files - again, I'm lazy.
6) I don't know jack about rooting? This is probably noob of me but I'm guessing may be some complications changing apps to run off sd card vs internal memory? I kind of just want to let the programs install the way they were designed to be installed/run. Thoughts? Caveat - this will be my first android device.