I don't drive below the speed limit as I feel excesively low speed (so even 10km under) is more dangerous than speeding as it frustrates other drivers so much, especially on single lane roads where it's difficult to pass. That's when accidents happen, when someone doing 90 in a 100 zone has a line of 5 behind them trying to pass.
I really dislike being a passenger with slow drivers especially on long trips as it takes so much longer to get somewhere.