Originally Posted by st patrick
It will, hopefully, bring in a lot more connecting traffic for Aer Lingus. If you have to connect somewhere to get from europe to your final/intermediate destination in the States, you may as well use the 2/3 hours allowed for your connection constructively by clearing immigration and customs, freeing you at the far end to just walk out of the terminal instead of "joining the line" for up to 2 hours.
The truth is that customs preclearance gives
no benefit to passengers using DUB to connect, unless they are connecting again in the US, so it's hardly a selling point. In fact it's a hindrance because it requires longer connection times. At least a larger CBP facility means more passengers can preclear immigration, which has obvious value.