Well, when I bought Grand Theft Auto San Andreas back in 2004 (I believe that's when it came out) It was for the Playstation 2. I never got the experience of these mods.
But, however, I did have Grand Theft Auto Vice City on the computer, and I tried the Multiplayer mod for that. It was really boring and wasn't really worth the effort of installing, but the San Andreas multiplayer mod is probably different in many ways, but I'm not buying/pirating the game just to check it out.