I have a three floors concrete residence. Currently using a Netgear wireless router + 2 extenders. VDSL comes in on the main floor with 25-40 Mb. Signal in the bottom floor is down to around 3-4 Mb. Considering mesh systems. Currently seems best systems are Linksys Velo and Netgear Orbi. Seems for me the Orbi is most fitting. Appreciate any advice.