Well I flew on the pre-clearance day flight to JFK yesterday. Went to first class lounge and around 8:20 they started telling PAX to go for the 10:30 flight. I waited some minutes, but started down there about 10 minutes later. But I took my time a bit. Security had special elite and first/business lines, but the line was actually longer. There were two global entry kiosks and no line for them. But the customs/immigration official did not know what to do with me when I handed the slip to him or her (the line manager put me in for the next available official), although she was nice and just said this was her first time to handle global entry. She didn't offer to show me my bags, so I asked about it, then she took my boarding pass and showed them. But she didn't seem worried about it. I then went to the gate. The gate, however, was not open and did not open until 15 minutes later, so I had to stand by the entrance (no real place to sit). Once the gate opened there was a separate section for first and business class PAX and there was another wait for the boarding to start. Boarding started about 10 am. The walkway to the plane is long and very hot this time of year, so I think it is worth it to get there in time for the early boarding of first and business, I would have hated waiting in line in the hot walkway. Many many wheelchair PAX, but fortunately they boarded after first and business. I think we left around 11 am, so only about 30 minutes late, and arrived in NY just about on time. Although clearance once I arrive is usually very easy for me with global entry, it was nice not to have as many PAX around the baggage claim since connecting PAX did not have to get their bags and re-check them and it seemed that I got my bags earlier (I think that the baggage claim people prioritize connecting bags when you have do the re-checking). But that was the only noticeable difference. I guess all in all my experience was not horrible, but I think I will opt for the 2 am flight in the future simply because I like being able to arrive early in the morning in NY rather than late in the afternoon in the future.