D_VoNFor those wondering, the reason it also comes with a separate WiFi adapter is so that you can have an array of 2 antennas, thereby making Multiple Input - Multiple Output (MIMO) possible. The Raspberry Pi by itself has only 1 antenna for both WiFi and BT (I think...)
JonHelgiData rate is not a priority for me, I just want to at least have a network with it in the 5 GHz band with a nice low latency. I don't think USB 2.0 makes the 5 GHz band impossible, just not the best performance. I also have some devices that just run better on AC type network in the higher frequency bands.
This thing you suggested is not only unavailable but also probably around $200 and requiring more parts to put to use properly, putting it outside my price range as well...
I'm not looking for a whole mini-PC, nor do I want some cheap RP 3 alternative from china like the Orange Pi
JonHelgiAlthough, for other reasons I think you are right. USB 2 is Half-duplex vs. USB 3 which is full-duplex. This makes USB 2 not very ideal at all for any kind of adapter