All PS3s play PS1 discs.
I think there is about 2 frames of input lag for both PS1 and PS2 games on PS3?
PS1 BC on PS3:
-Uneven upscaling
-No 240p
-Some games look soft, others are rendered sharp
-The odd graphical glitch
PS2 BC on PS3
-Aspect ratio is different between full hardware emulation and partial PS3 bc variations (not sure which is correct)
-The odd graphical glitch
-Deinterlace errors