I decided to tackle this issue and have a short conversation regarding the PS4 after having to buy an external hard drive, myself not being acutely aware of, what I believe, is the PS4's storage problem.
The PS4 features 500GB worth of storage which is normally nothing to sneeze at, however, for some reason the games (or applications as PSN calls them) take up an awful lot of space. There may be a ton of different factors that go into this but I find it extremely odd that a disc game like "Witcher 3" can take up 40-something GB and a digitally downloaded game like "Darksiders" takes around 30.
One might argue that it's perhaps the massive scope of the "Witcher 3" but given that it's stored in a disc, makes me question the need for such a hefty amount of storage needed for the application. Even without all the expansion, the vanilla "Dragon Age: Inquisition" still took up around 40GB. Moreover, there's little consistency as to why these titles have such varying degrees of storage toll - "Bloodborne" and "Tomb Raider" were around 16-17GB, "Persona 5" and "Darksiders II" around 20GB, but the others mentioned quickly rocketed up the ladder.
Compared to the Xbox One (which my cousins have and who have barely scratched the halfway point of their 500GB drive) it makes me wonder why the PS4 has such a storage issue. Sony tried to remedy this with the Pro version which boasts a 1TB drive (but honestly, for the added price, you're probably better off getting a vanilla PS4 and supplementing it with an external hard drive). I bring this up because it was an issue I was completely unaware of and think it may be a point of interest for gamers debating which next-gen console to splurge on.
Though I previously went for the Xbox 360 over the PS3, I decided to go for the PS4 because of console exclusives, namely "Persona 5" and "Bloodborne" (Microsoft's exclusives didn't really grab me). Had I known about the storage issues I would have still probably gone PS4 but like I said, it's an important factor to know about regardless.
This is not meant to be a rant but rather an observation on a caveat of the system and as a method by which to disseminate the information to someone who may be on the fence about which system to buy. Again, if you were unprepared for the storage issue or just unsure of how to address it, an external hard drive is a good move. Not only is is portable but they run around the vein of 70-100 dollars.
I was able to snag a 2TB external hard drive for 75 bucks, quadrupling my storage as opposed to doubling it with the Pro.