Just today received a twin pack of Deco M4, put my Virgin Router in Modem mode, downloaded TP Link app and ran through the wizard, must of took around 10 minutes from start to finish.
Ditched my old Powerline adapters, works a treat and been great all day. Only time will tell but happy so far. I found with the Powerline adapters they worked fine for around 30 hours, then I’d have to reboot them.