Yes, because the 30 seconds it will take to switch discs twice (there are only 2 disc swaps in the entire game) is so much longer than the 30 minutes it will take to install the game, download the update, and install that before even getting to the title screen.
So if it is 30 minutes to install the game on ps3, it is going to be even more time when installing on 360, not to mention you still have to swap the disc when it tells you.
I'll take the PS3 version (it also has an exclusive mission.)