"Deploying on anything other than 1, 6 or 11 will cause more problems than it will solve," This is a fundamental mistake. You are correct that the transmit ma

"Deploying on anything other than 1, 6 or 11 will cause more problems than it will solve," This is a fundamental mistake. You are correct that the transmit mask of WiFi allows for 3 'non-overlapping' channels in the 2.4GHz band, but the receivers won't allow simultaneous operation on these three channels since the advent of 802.11g (and 802.11n made the situation worse.) The receivers don't have enough adjacent channel rejection (ACR) to deal with a strong (i.e. closer or high-EIRP) signal on an ajacent channel. At 6Mbps, the IEEE standard requires 16 dB of adjacent channel rejection. The amount of ACR required by the standard is lower as the modulation rate increases. At 18Mbps the IEEE standard requires 11dB of ACR. At 54Mbps, the ACR required by the standard is -1dB. While some chipsets perform above these requirements one has to assume that the clients perform at the minimum, since there is no way to control what client will wander into the room next. Nobody wants to believe it, but the way to make 2.4GHz WiFi work for large conferences is to run all the APs on the same channel (in any given 'band')