My mom and grandma use it as their only computer. They keep running out of storage space because they use it to save photos from their digital cameras. My mom is by no stretch of the imagination a power user, but she is always running low on her 32GB iPad 4th gen. I've got my grandma setup with Dropbox on their 16GB iPad 4th gen, but will probably switch them to iCloud Photos when that goes live because it's a lot easier to manage and automatically keeps cached versions in their camera roll.
As for me, I keep a cache of my Lightroom Library on my device which takes up several gigs. I usually have a movie or two for the airplane, a few large Rdio Playlists cached offline which takes up a few gigs, a bunch of photos and videos I take of my baby daughter and wife, sketches that I make with Adobe Ink & Slide, AAA 3D games like Bioshock, and bunch of cached iMessages (hopefully this will be lower with the new iOS 8 settings—but I wish there was a 3 month setting instead of 1 year and 1 month), apps like iWork and iLife take up a lot of space, along with some reference guides like Peterson birds and FontBook—as well as offline maps in Navigon in case I get into a situation where I'm lost without a data connection. I also like having a lot of extra space so that I can dump my RAW photos from my DSLR. I just wish Lightroom Mobile would update so that it can import those, let me organize them and sync them back to my Mac while I'm on a trip. Apparently iCloud Photo Library will sync the RAW files up and back to the Mac, so I'm definitely going to use that when it comes out. I've already purchased 200GB of iCloud storage. I'm really glad that I got the 128GB iPhone 6 Plus because now I don't ever have to worry about managing space. I'm probably considered an iOS power user.
As for me, I keep a cache of my Lightroom Library on my device which takes up several gigs. I usually have a movie or two for the airplane, a few large Rdio Playlists cached offline which takes up a few gigs, a bunch of photos and videos I take of my baby daughter and wife, sketches that I make with Adobe Ink & Slide, AAA 3D games like Bioshock, and bunch of cached iMessages (hopefully this will be lower with the new iOS 8 settings—but I wish there was a 3 month setting instead of 1 year and 1 month), apps like iWork and iLife take up a lot of space, along with some reference guides like Peterson birds and FontBook—as well as offline maps in Navigon in case I get into a situation where I'm lost without a data connection. I also like having a lot of extra space so that I can dump my RAW photos from my DSLR. I just wish Lightroom Mobile would update so that it can import those, let me organize them and sync them back to my Mac while I'm on a trip. Apparently iCloud Photo Library will sync the RAW files up and back to the Mac, so I'm definitely going to use that when it comes out. I've already purchased 200GB of iCloud storage. I'm really glad that I got the 128GB iPhone 6 Plus because now I don't ever have to worry about managing space. I'm probably considered an iOS power user.