The only big advantage with a fast line is on patch days. You get the updates very quickly (and yes, I have 4mbps). If you want to upgrade, I suggest you wait for Telkom to fix the issues they're having with the line atm - most people are getting disconnected a few times per day, getting authentication errors, and their line speeds drops down to 192-384kbps speeds after a while, forcing you to reset your modem/router to fix it (which forces you to deal with the autentication errors again).