You're on your way then pipsi - great getting real time updates.

People do say you should go to pre-clearance early since it can take time to get through and the flight won't wait for you. The one time I have taken the AA flight to JFK from DUB I didn't really see any queue. My only problem was trying to explain to the Border Control guy what this TP running was all about. I was on the way to GCM via JFK, LAS and MIA and coming straight back! We had a chuckle about it in the end though. He called me crazy...

Have a safe flight.