200-600 meg pretty fast so why hype? British Telecom, despite the BBC and other news reports, did not attain a gigabit with G.fast. They merely showed that 104 MHz over a protected standard copper line could reach speeds of 786 megabits down 19 meters, something obvious for years from the basic engineering. The substance of G.fast is significant so the hype is unneeded.
BT's results were not for G.fast. G.fast is a 300 page specification that BT/Huawei didn't even pretend to support. Many features, such as reverse power, are important and were not implemented. Vectoring in G.fast remains totally unproven and will be crucial to any deployment. Several features of G.fast are likely to reduce the speed. The effect may be relatively modest but we won't know until they are tested.