The best ADSL throughtput in SA at the moment is definately a SAIX provided connection.
Craig .. if you are going to actually chew 30GB then i'd say that AYCE is a good account. I use their 10GB one [which they don't sell anymore], and have absolutely no complaints.
But - ask any ISP, they're all listed at
www.hellkom.co.za, and just make sure that their back-bone is SAIX and not IS.
P.S. IS say that they will have upgraded their sattelite link soon [1 or 2 months], and their capacity through rosebank is also in the process of being upgraded [1 or 2 months], and that should solve their current problems, but , until they actually have solved their problems, i would not touch them.
We're dropping IS from our company as a whole because they have failed us once again. We are now unfortunayely becoming teklom whores

, well - as soon as the contracts finish or our lawyers have won.