my unifi had been upgraded from 30mbps to 300mbps, I had upgraded my router to gigabyte router ( prolink PRC3801 and the TPLINK archer C1200, i redo my back bone from main router to room router using LAN cable cat 6, ( I had two tplink power adapater 1300 mbps for sales , few month old only)

Speed with cable and gigabyte lan can to to max 300mbps,With my latest P20 pro i can get close to 290mbps when less then a meter within the router at 5 G , if i stand within 3-5 meter the speed drop to 100mbps....

Still aplenty , on 2.4G wirless max out about 90mbps... so to get max 300 is almost impossible if you not connected with LAN cat 6 cable or less then a meter.

Anyway 100mbps per device is good enough