802.11ac is the same as 11n in the 2.4 GHz band. All the new features are for the 5 GHz band, and its support is required for 11ac. At 5 GHz there's plenty of s

802.11ac is the same as 11n in the 2.4 GHz band. All the new features are for the 5 GHz band, and its support is required for 11ac. At 5 GHz there's plenty of spectrum so wider channels still make sense there. But not at 2.4 GHz indeed.