Rockstar says for 360 version do not install both discs.

[attaboy]

kowenicki said:

attaboy said:
I can't think of a single reason for this. I don't like it, though. I'm sure it wouldn't happen often but I remember how pissed I was when I played Metal Gear Solid 4 and I was ready for the game to continue. Instead, I had to wait for the game to install. I think I'll get flashbacks with GTAV.

thats not what this is.

I think I got the gist of it.  Metal Gear was on one disc and had to install between chapters.  From what I can tell (I prefer to install discs like I did with Mass Effect 2 and 3), somewhere along the way, I'll finish disc one and have to install disc two.  Right?

*edit* and if I had to go back to disc one (for example, if somebody else wanted to play and we were on different discs), I'd have to uninstall disc 2 to reinstall disc one.  If that's not what this is, I apologize for jumping to conclusions.