I'd rather arrive at 11 than 6 mainly because then it's lunch time when I get into the city; there is not much to do at 6am (or 7:30 or whenever I'd be in the thick of things). Also, the later flight probably means I can work a full day before getting on the plane (if coming from the east coast). I do find that I'm so excited to begin a trip that I'll have energy regardless of when I arrive.

I've long had a theory that the best departure time for any flight over 3 hours is 2am, though. For me it's the best use of time before and after the flight.

Seth