Just came back from there. I used the machine at the check in counter (avoided teh really long line). Went through security. Then at the gate (or if you arrive at the gate more than an hour early the transfer desk) they do some supplemental screening questions (have your bags been in your possession . . . ). Then you get a sticker on your passport and you're done.
None of it is an issue. If you arrive 3+ hours early you can sit around inside security until flight time.