So I use two of these in a 2000 Sq. Ft. house, and they still report 25% of my clients are weak, 50% are OK, and 25% are good. Now here is the crazy thing. They report receiving "interfering" access points miles away. So I receive 142 rouge access points, (with widely spaced house) but the signal to my CLIENTS INSIDE my house get a weaker signal. Go figure.
Update: So since WiFi is a two-way wireless signal, it turns out, turning way DOWN the power of this access point helps. If your phone can only transmit at a low power, it doesn't help to have an AP at high power.