It was a surprisingly long walk from our gate (45-60 minute walk!) but immigration was a breeze and the Emirates car service is organized and efficient. The airport itself seemed fairly quiet, but it's a huge place so it's hard to tell. There were certainly no lines anywhere.
Our friendly Emirates driver was from Uganda, and he obligingly pointed out sights during our 30-minute drive to our hotel, including the world's tallest building, the Burj Khalifa.