If we space recepts 12' apart as allowed by code, 3% drop allows us 5 recepts (60') and a 5% drop allows us 8 recpts (100'). Either seems a bit restrictive.
I would expect that if there was a real world problem (circuits drawing 80%) more people would be using shared neutrals.
I suspect that most high current loads are heating loads, including hair driers. For those voltage drop is not as important.
