Experience with Archer C7 covered in the thread above.
To significantly outperform an Archer C7 or devices in its class, you likely need an ARM or x86_64 / AMD64 device, which probably still puts you out of the
class and into the range of
or discrete x86_64 / AMD64 general-purpose unit configured as a router with external AP(s) (for which the Archer C7 is a reasonable option at US $40, used)