You should read the links you cite before you cite them. Among the answers found on that page are these:
"The 1-6-11 recommendation contained in Cisco's whitepaper about IEEE 802.11 deployment in the corporate environment certainly does not apply to all circumstances! For example, in moderately congested neighbourhoods, one stands a very good chance to benefit from not sticking to this proposed scheme."
"the situation usually gets worse when one voluntary abides to the 1-6-11 non-overlapping channel scheme. Doing so will expose your devices to the IEEE 802.11 RTS/CTS/ACK (Request to Send / Clear to Send / Acknowledge) of alien devices, effectively silencing your devices and hence forcedly lowering your bandwidth. This problem is known as the exposed node problem. In a corporate setting this problem can be solved by synchronising the nodes. In the wild, this is not readily achievable."
"In big corporate networks it's common practice to use channels 1,6 & 11 because it is fairly straightforward (at least on a diagram) to design non-overlapping cells of coverage. As a home user you don't have the same constraints so it makes sense to experiment and look for the best channel."
"I am a Ham Radio operator. I have done extensive testing. On my Actiontec or ZyXcel, channel 1 is abysmal! Channel 11 is a close second to the death of channel 1. ACTUAL power readings put 3 and 4 as the strongest signal output and throughput. Channels 6 and 9 are the standard preset. so actually avoid 1,6,9,11. I am a DSL tech also. I have walked people through changing channels from 9-10-11 to 3 or 4. They are amazed at the doubling of the wifi signal on all devices across the board."
"Hence, I call for actually measuring one's own signal-to-noise level...The Quality value takes into account noise from overlapping channels."
The bottom line is as I said: test your own equipment in your own environment and find what works best for you.