it is worth to buy ($40) a wifi USB 3.0 wifi ac card to speed up wireless network (upgrade some features, login with apple watch for example)? Maybe it will be an unnoticed change. Has someone experience in this matter?
Since no one has chimed in with definitive knowledge you're best bet is probably going to be perusing reviews for USB AC wifi adapters at Amazon to see if anyone has successfully done what you're wanting to do.