@Ivaylo thanks for the response. My C80 has in fact the address http://192.168.0.1. 

My ISP modem Router is in one room and provides good WiFi access there. 

I wanted to use the C80 as a simple WiFi extender for the rooms in the back of the house.

At the moment the performance at 2.4 is excellent. 

5Ghz even better when testing from 3 devices at the same time with WiFi Sweetspots mobile app.

Will do some testing as access point to see if I notice any performance difference.

cheers Matt

@Ivaylo I knew that the typical use case for AP was extending the WiFi coverage. I just wasn't expecting that the normal router mode would also work. I just inserted the ethernet cable and boom , my internet was working... so my first thought was : why AP mode if router mode works as well.

Did some testing and definitively AP mode in 5Ghz is about 10% faster in each value I see in 3 parallel WiFi SweetSpot mobile apps running at the same time.

Will keep AP mode and monitor stability of the connection ...

Again, thanks a lot for the help 

@Ksmbo 

There is one major difference between router mode and access mode. In your case, in access mode a device connected to your c80 can see other devices connected to the main router because every connected devices are in the same DHCP pool. In router mode on c80 it would isolate its sub-network from the other part of the network connected to the main router.

I'm surprised about your result that access mode would be 10% faster. This router is not an entry level budget product. Its performance should be more firm in router mode.