Wi-Fi mesh systems are the future of home networking. Mac Observer has a really good run down on what they are and which one is best for your home:
Mesh routing completes that puzzle because the access points act as one. They are all aware of each other and can work with client devices to decide which access point is best for that client at that time, not just which one is closest or has the strongest signal. If one device starts streaming a ton of Netflix, for example, the mesh can identify this and either tell that client to move or start moving other clients to free up that radio for the video stream.
This kind of setup is simply not possible to build yourself with off-the-shelf routers.
My place isn’t big enough to need something like this, but damn, it’s still cool.