One of the best USA Pre-Clearance US Immigration areas I have seen. They only allow 1-2 flights in…read moreat a time, whatever is departing next. Which is nice because it keeps the line moving, and there isn't much "on the other side". So you could spend extra time on the Irish side and then hope through pretty quick to get your plane.
It took us about 10 minutes to do the extra security screening and the actual immigration interrogation. Not bad at all. They were doing 2 flights from SNN to ORD and SNN to EWR, both United flights on 757-200's which means just under 400 people possible. It was smooth, efficient, and couldn't really have been much better.