no you do not need the 32GB model. even if you find you do need more space later, you can get a wireless hard drive for the same price, with 500GB of storage. that to me is a no brainer, and a wireless drive can easily be mobile.
the issue with 32GB is, if you need 32GB, then you probably need MORE than 32GB. if you can go through the trouble of toting around a tablet, then you can go through the trouble of toting around a 500GB wireless drive.
Let's say you're traveling and think you need 32GB of storage to have content to view for when you're unable to get internet access....well if you're going to be without internet access for days or more at a time, 32GB will probably NOT be enough, especially if you want to watch 1080p.
and if you're going to be primarily using your tablet at home and have internet access always available, 32GB is definitely not necessary. I stream files directly from my PC. nothing but apps and games on the tablet, and I rarely go below 10GB free space, and when I do, it's not for long because I uninstall big games when I'm done playing them, and I can't possibly see why someone would need even 5GB worth of games on a tablet at a single time.