My international on saix has been terrible. I have a telkom 4mbps line, and using a 10gig shaped acc from webafrica. Its really slow, I am lucky to get 128kbps during the day for international. Local stuff is fast and fine. They keep trying to say its my router or the line, but I know its not. I have this sneaky suspicion that the pool of transparent proxies that saix forces everyone through is totally congested.
Complaining to webafrica, they got me to send traceroutes for various international sites to them to forward to saix/telscum, but that hasnt solved the problem in the long term. (It seemed to be faster a day after moaning, then went back to slow)
Note that traceroutes wont tell you a thing if your connections are being subverted to a sucky transparent proxy.