Sorry didn't answer the other part.
If the card and router is compatible with 5GHz (didn't check) and you use the computer on the proximity of the router try that it will give you more speed and usually the 5GHz spectrum is less saturated, at my home I can detect around 15 2.4GHz wireless networks and only 2-3 working on 5GHz.
If the card and router is compatible with 5GHz (didn't check) and you use the computer on the proximity of the router try that it will give you more speed and usually the 5GHz spectrum is less saturated, at my home I can detect around 15 2.4GHz wireless networks and only 2-3 working on 5GHz.