At SEA they had citizen lines and visitors/green card lines last I went
through (used to have residents/citizens and visitor lines for years of
coming in that way in the past, don't know why it changed) so I think
it really depends on the airport as well as your resident status. Our
family went into the visitor lines because only 5 of us are citizens.
They had people checking those trying to use the citizen lines.

It really wouldn't matter what line if it were quick and pleasant to
use any line. All lines were long and unfriendly; they really have
a fantastic ability to discourage tourism.