Asus dsl-n66u modem/router on infinity

Has anyone had any joy with one of these on fiber/vdsl/infinity ? been trying to get one connected up supposed to be a 30 second setup lol..... have tried all the firmware available can run ping tests from the tools inside the router but totally no thru put from wifi or lan even once showing as connected .....there are post on how poor the stability is but not many nor many saying its good BT shop still sells this product just wondering as ive tried almost everything must be something daft im not seeing ... has anyone got one working ??