If compression is the key, the PS1 would of used cartirdges, and PS2 would of used CDs etc...they didnt...
As time goes by games get bigger. Very easy to understand, before you could get games on those little floppy discs and computers came with 2GB HDD...then games started coming out on CDs and HDD were 30GB...then DVDs and HDD are 200GB...
360 will soon hit a bottle neck in space constraints...the PS3 outsells it every week and is closing in on total sales....without the hassle of mass compression and games on 4 discs...what do you think developers will do then? Once the Ps3 overtakes the 360 in sales and breaking even is no longer a concern because the PS3 has more marketshare and can sell more games do you think develops will hold their ideas and technological break thoughs back? No they'll develop to their hearts content...
It's like buying a house and you know you have kids on the way...do you buy a studio condo(360) which will run out of room fast or buy the family home(PS3) which will accomodate your family?
In my opinion the 360 is doomed to an early exit this generation...we seen how quickly the Xbox was done...PS2 has over twice the life...Im not going to pay for something when the competition offers double the life span.








