One word of advice w/ regards to what others on the internet say they can do with their wireless setup - Irrelevant.
I'm not saying anyone here is fibbing. Wireless transmission is a black art and there are a lot of individual issues that will affect it (heck, I can watch my wireless throughput take a dive and then recover every time a light aircraft flies by as it comes in for a landing at a local airport close by our house.)
Don't spend endless days trying to replicate the same performance that someone out on the internet says they can accomplish by just using this or that setting. Their location, interference, competing wireless transmissions around them, etc. etc. are all completely different from your situation in your house.
If you are having problems, pull a wire and be done with it.