you guys have made me jealous

the ac66 is a first gen ac product so I guess its to be expected it wont perform optimally, I think the extra speed of the 5ghz is expected because of that. But seeing double performance is indeed impressive but since I only got my ac66 less than a year ago I am not going to replace it yet.
My only 5ghz product is my phone, and the speed I get is easily good enough (after applying #a), my laptop which I do copy files to/from is 2.4ghz only. However my spare pc does have an AC dongle in which I just remembered about, will check its performance later.