The 80's are not entirely software emulation. As far as I know they have one of the 2 chips required for full hardware emulation. I believe they have the PS2 graphics chip but not the CPU which is whats being emulated. The 60gb of course has both chips and should be 100% bc. The 80gb is mostly compatible but you might want to bookmark
PlayStation.com - Support - PLAYSTATION®3 Backward Compatibility Status and make sure the games you want to play dont show any issues. For what it's worth I have a 60gb an I love it.