Any tips on getting through quickly or quicker?
Global entry is hands down worth it for reducing wait times but it’s for frequent travellers not the odd family holiday- it’s a lengthy application and you need to be interviewed by TSA.
I’ve done the Ireland connection in the past and I’ve found it adds more time to your journey that you’d typically wait at the border (even before I had global entry), although they were quite nice there.
First class gets you off the plane first so if your power walk you’re ahead of all your fellow passengers- no special line though!
A quieter airport rather than a big connection hub is probably quicker but I’ve never tried that.