I am paranoid about internal storage.
When my Evo 3D suffered a black screen of death (a known issue on Evo 3D), I had to do a factory reset and it wiped out all of my cool 3D photos and videos that were stored in the internal storage by default.
Now I always use external SD card storage to store my media, in case the phone has a catastrophic malfunction, gets dropped in water, etc etc. If it's in internal storage, kiss it good bye.
The relative minor "hassle" of having an additional place to store my media is far outweight by the opportunity of having my data easily accessible even if the device were to take a dump.
Using tools like any of the plethra of the file explorers available on the Play Store you can easily understand the structure of the folders and know where things go.
This is a complaint for me on the PC side of things too, when too many people give me blank stares when I ask them where their data is store on the PC. You should know where your files are, it's pretty easy to find out and keep track of it.