I used Preclearance in DUB they had Global Entry, too. Too bad I got the dreaded SSSS designation on my boarding pass but it was just a minor residue check and took very little extra time at security. They do a general scan for entry into the terminal, then a more thorough one w/ shoes off, liquids out, etc, just before immigration Preclearance. The other nonrev following me didn't have GE, so I said I'd meet him at the gate. He got there 50 minutes later. I took my 20 seconds at the kiosk and fast-tracked straight to CBP officer (no line for GE holders) who said, "welcome home". Saved me a lot of anxiety and time. Then the flight was delayed by late arrival. I found the crew at the gate so I hung out with them for a while. It was a nice 24 hr trip.