Okay, details below. I thought you were all so experienced you would advise me with some "common accepted wisdom."

This is an AA itinerary, the return from JFK-AYT (Antalya, Turkey).

Airberlin Seat information not available Meal: Snack
Aircraft: 738 Booking Code: X
Cabin: Economy

BA 983

2:05 PM
TXL

3:00 PM
LHR
British Airways Seat information not available Meal: Snack
Aircraft: 321 Booking Code: X
Cabin: Economy
107

5:05 PM
LHR

8:15 PM
JFK
American Airlines View Available Seats Meal: Dinner Snack
Aircraft: 77W Booking Code: T
Total Travel Time: 16hr 20min Cabin: Economy