I have a five room, 114m^2 (1200square feet), single story apartment. I have two routers set up. One working as a proper router and one functioning as a pure WAP (it has wired access itself). It is very clear from careful measurement that I definitely need two routers as opposed to one to get good WiFi coverage in the whole apartment.
I have set up these routers in opposite ends of the apartment (It would perhaps have been better to have a single router in the center of the apartment, but that is not possible for several practical reasons).
Now, I already own a third router (hardware identical to the WAP) that I could set up as a second WAP, potentially forming a fairly equilateral triangle of routers. The third router would also have wired access itself.
Will I get even better WiFi reception with a third router? Or will the routers interfere with each other, and perhaps even make the reception worse? (It is a big apartment house, so there are already plenty of WiFi routers in the vicinity)
The hardware in question is an ASUS RT-N56U Dual-band Wireless-N Gigabit Router Router as main router and two Netgear WNDR3700v1 (running DD-WRT) as WAP. So all routers have dual-band, support 11n, and are fairly high-end. They are all configured to auto-select appropriate channels.