mandatory installation is the worst thing? Then what do you call RROD?
And to answer about how PS3 20gb owners can't play 3 games at the same time. Of course you can't! You can only play 1 game at a time even if you have 500gb of hardrive even on the 360.
Don't freakin exaggerate the installations. Sure they're a little annoying but it just take some minutes not a whole day. And oh yeah, you can upgrade your HDD FYI.