All that said, the article does manage to skim over a few things it should have talked about. There are actual physical differences between the cabling specs which are a result of the 6A signalling requirements. The termination is _MUCH_ stricter and likely the cause of 99% of the failures in cases where the cables actually are 23AWG, properly twisted and isolated. Its these latter three things which will allow you to identify "real" cat6A rather than the stuff being relabeled by cable manufactures claiming to have found some secret method of making what are basically cat5E cables 6A.
(back to my 5e comment. The thing to keep in mind about a lot of this is that the standards specify minimums. The whole cat5E grouping was one where there was a race to out-specify everyone else, which is why you can find cat 5E 500Mhz labeled cabling, although most places just renamed it to cat 6 and charged a few cents more per foot. The other thing to keep in mind is that these specifications end up being given in loss/crosstalk per foot, so its quite possible to run higher data speeds on short cables that are non compliant per foot, particularly if they are terminated properly. Hence other comments I've made on this site about running 10GbaseT in my house on cat5E without any apparent signally/packet loss due to the runs all being very short.).