I recently purchased a Deco X55 3-pack and it does not appear to support what I think of as a mesh topology. 

We live on an old farmstead with three building (the main house, a stone summer kitchen and a small office) roughly in a row about each about 20 ft apart. I expected the mesh units to automatically connect to their nearest (strongest signal) neighbor and relay traffic. However, it seems that each "remote" Deco unit must connect the main unit (via WiFi or using Ethernet back haul). Is this correct?

Based on our usage and the building construction, it works out best to place the 300/100 Mbps G modem that provides our internet service in the office which is the west-most building. I'm having problems getting enough signal to the Deco in the house which is the east-most building. The summer kitchen is between the house and the office and I expected to use it as a relay point but can't seem to configure the system that way.

I've tried using AV1300 power line Ethernet but only get about 10 Mbps between the office and house using it. Even with the weak signal, the WiFi connection between the house and office Deco units is better, at about 50 Mbps (using 2.4 GHz I assume).

Any suggestions of how I might best configure my setup to get better speed to the house?

Note - My hardware version is US/1.6 which was not a choice in the message menu.