
Some of Yifan Lu’s interesting findings are that the eMMC NAND is about 3.78 GB, with about 800 MB used by the (encrypted) system, and the remaining 3GB or so potentially empty for now.
Wonder if this could allow the VITA to have a complete OS overhaul.
Anyway, here's what seem to be an interesting point by n00bsaib0t (gamefaqs user):
Probably nothing. Android phones were doing this same thing back in the day when their internal storage was for apps only. You would buy a phone with 2GB storage and only get access to 512MB for apps with the rom taking 150MB at the most leaving over a gig inaccessible.