So to sum it up: if you spend a lot of time in areas without internet connectivity, you watch movies, series, listen to music, read graphic-heavy magazines and you play 4-5 games at a time, get the 32GB one.
On the other hand, if you use it mostly in areas with good internet coverage or if you have an unlimited data plan, and only for browsing the internet or streaming, get a 16GB one (+cellular).
So basically think of what you'll be using it for and make a smart decision.
I personally have a 16GB iPad2 and I never managed to fill up more than 10GB. I don't use it for anything else but browsing the forums/reddit/news sites, watching my youtube subscriptions, RDP-ing on my home PC and I don't really play anything but mindless games with crap graphics, that's why I am going to get a 16GB iPad Air on friday and put the difference towards some nice custom JH Audio IEMs.
But, I have a 64GB iPhone to keep my music on and I wish they made a 128GB version.
And even if you are short of money now, you can later get one of those WiFi drives, like Corsair Voyager Air which for $150 offers you 500GB of storage that will put those 128GB iPad/Bentley owners to shame
