The time saver will be that you don't stand and see an immigration officer. Remember facial recognition has been a part of Jamaica immigration for many years. When you step up and see the immigration officer, and he is flipping through your passport, talking to the other officer and checking his/her phone, what they are really doing is waiting for the facial recognition cameras up above to clear you. Ya 2-3 minutes tops but times that by 100 people waiting in line. Now the facial recognition camera is right there, out front and gets you picture right a way with no waiting. I agree with Rob, this is a game changer.
Now the real problem is the outside of the airport. They changed the direction of traffic entering departures 3 days before Christmas with little to no notice or signage, and now they switched it back to the old way. The old gas station is gone while they make more parking but in the mean time parking is a problem while they work on it and traffic is backed up. It's going to get better but right now it's a nightmare to get into the airport.