This sounds plausible to me. Here in Omaha, when I lived in an apartment and there were 30+ APs visible I had to be careful to pick the frequency based on what worked and what didn't, and when I did get it to be reliable I had short range. I am pretty sure this was just because of noise and cross-talk.

Now in a house I see maybe 10 APs and they are all at the edge of their range and I rarely need to tinker with it and it works all the way across the street.