I've gotten the 1TB version since it was available. On mine I have a healthy collection of comic books from Comixology, as well as a large collection of personal manga, magazines, and comic books on a comic book reader app. There's also my healthy iTunes collection of music, movies, and TV, along with backed up video I watch with Infuse. That alone is easily 250K.
I also have some large project files split between Clip Art Studio & Procreate. I always hope one day to learn stuff with video, which would be another large chunk.
So I like knowing that I'm in no danger of running out of room. The days of figuring out what fits on my device are long gone for me, and I can't always count on internet access for getting things from the cloud.