Emulators have far too much input lag VS real hardware for me, even if you use the real hardware with an OSSC or something, the TV still adds far less lag. I know that's not cheap, but I love the real hardware. Says you clearly if I paid over 200 for a line doubler
Some games are OK as you wouldn't notice the input lag too much, but games like Rayman 1 and 2D Mario you will really notice the difference if you're used to playing the game on original hardware.
That said though I guess emulators kind of do count since you're still playing PS2 games