We got there a little over three hours prior. The longest line was checking in since nobody was there yet. There were a few ahead of us; but a very long line behind us. Even bought a few things prior to going through customs and the clerk met us on the other side.
We got through customs very quickly.. had lunch and more shopping. Was overcharge for some dark chocolate and the clerk actually closed his store and looked for us for a few dollars. Very nice so I went back and got more chocolate.