texasels, you are wrong. Not just netvigator, but other ISPs have also had a serious decrease in performance even have broken pages which don't load on both Netvigator and Netfront.
yellowtip, as I said, you are paying peanuts for your circuit and when conditions are bad this is what happens. Be realistic and don't expect better. Your circuit is most likely to be 100Mbit FE port. So at 300KB/s you are getting about 3Mbit, or 3% international of what your circuit can do. On diyixian I get at least 50% international of what the circuit can do, mind you I do pay a 4 digit figure for the circuit. You get what you pay for.
You are on a network where the users have such big ports (FE,GE) that ratio of user port bandwidth to international circuit bandwidth means that it will always be easy to congest the international pipes. HKBN selling FE and GE ports does have this inherent weakness. Looks good on specs 100Mbit, 1Gbit circuits, but that is all, you get 3%.