With all the benefits gained by using Blu Ray as the PS3's default storage media, comes a whole host of cons accompany it.  The largest issue is the slow disc read speed of the PS3's Blu Ray drive, which has essentially forced a lot of developers to install data on the PS3's hard disc drive to keep the game running quickly.  Some games, such as MGS4, even resort to installing and uninstalling whole entire sets of data in between acts, making it impossible to quickly access saves from different parts of the game. 

Sucker Punch's Brian Flemming spoke a bit mandatory installs, saying that the developer believes the first 15 minutes of a game are the most crucial to pull gamers in, and that an install in those first 15 minutes kills that immersion. 

"[The first 15 minutes] is where people will transition from the world that they have into your universe. And you have this chance to get them and move them into your space, and capture their attention. And if you **** that up, whatever you did in that last boss battle just doesn't matter."

Flemming continued, explaining that while they are still toying with when, where, and how to place mandatory install, "that 15-minute install is an absolute non-starter for us".  

Check out Flemming's full interview here.