How can 16GB not be enough for apps? I'm really just wondering, not meaning to troll. I have more than I need in about 2GB: maps, facebook and a few other social networks, VNC, terminal emulator, some work apps like Trello, and a few toys. Do you need to have twenty variations of Angry Birds available at all times, or what?
Further down the tangent, I also don't have trouble keeping a good supply of music without using any cloud bullshit. It's not hard to set up syncing to rotate your music often enough to keep things interesting (while maintaining a core playlist of favorites). I guess if I had to go on a sudden multi-day hike through remote wilderness, I would run out of music, but that's not really a concern. I avoid cloud/streaming shit like the plague, and still consider the SD slot to be a negative; it takes up space, is failure-prone (in my experience at least), and contributes little.
On topic, I wouldn't mind if there were a notice like (*: Operating System occupies 3GB of space. Future updates may change this capacity, see inside for details), but I still think that this falls into the "common knowledge" side of things, like knowing that a 2x4 is measured in the unprocessed size, and in reality it'll be somewhere around 1.5"x3.5".