No lag? Are you playing your neighbour kiddy corner to your ISP?
Anyway, most types of games can manage over a dial up connection, but try playing with dial up in a FPS, with a 6, 8, 12, 32 players and see how well it goes. That\'s when you\'ll have problems.
Or just look at the DC for a pretty good idea of how things are going to be on the PS2. Football will be okay, FPSs will be boarderline playable or look at a game like Chu Chu Rocket--lag ruined that game.
If it\'s a game that is fast and requires split-second timing, lag will get in the way. It will still be playable, but it will frustrate you and kill you at the most inopportune times (or so it seems).
I for one will not play a single PS2 game that uses both dial up and BB. I cannot go back.