Well, like I say, my better result might be (probably is) random. The logician in me says my built OS install must have a default setting that is incompatible with N. The question is, which one? For instance, I read about a duplex setting in advanced adapter settings for Microsoft Client. Thing is, I don't even see such a choice in my drop downs, so it was a dead end for me.
Someone might like to test a Windows 7 box N and G, see if indeed there is a notable difference, and be in a position to pass that along to others in my situation. Also see about my MIMO (sp) setting, Auto vs picking a setting.
Personally I am done tinkering for the time being. I have 6mb download and for what I do and where the machine sits in the house, "enough is as much as a feast."