I am US based, just to help with your advice. So am I of the understanding that given that distinction, both airlines offer the pre-clearance benefit coming back to Dulles? Or is it just with Aer Lingus? I have read about the customer service complaints for Aer Lingus, but also some decent reviews. I have only flown non-stop previously, and do worry a bit about lost luggage if we were to check anything, esp for the arrival, but if it’s only for the short leg to LBA, I think that would be ok? Thanks for the information as I weigh the pros and cons of each.