cjcool804 on Twitter posted yesterday that the PS4 Storage only allows just over 400GB of Storage. The good news is that the 84GB of used storage was from 3 games. Bigger games may reach up to 50-60 GB each but we may be able to fit a few more games than originally expected on the drives. Most users will definitely need to do a hard drive upgrade for the long term.
The three games that cjcool installed were:
Madden NFL 25: 15GB
Call of Duty Ghosts: 32GB
Some more looks of the PS4 from cjcool804