Same as you, I've got way more content than 128GB. I don't even have any music or videos on the iPad, it's just all graphic novels (Japanese manga mostly). However, I went with 128GB instead of 64GB. Having 128GB requires much less management than 64GB. I have favorite manga that I like to keep on hand at all times. The 128GB gives me a lot more breathing room. On my 64GB iPad, I couldn't even update my GPS app because storage is always full (like 200MB-1GB free).I flirted with 128, but went with 64.
My reasoning was even with 128 I'm still not going to be able to fit ALL my music, films, photos, apps, books, etc.
I'm still going to have to pick and choose media.
Even if Apple offers 2TB cloud storage, I still wouldn't bite unless they also give me an unlimited 1Gbit wireless connection.Until Apple offers 2TB of cloud storage, I'll always have to manage media.