I prefer 3J, 2J is fine too.
Also usually a good hedge against switch to coffin seats which, while disappointing, is not exactly the end of the world especially if its a non bulkhead window (IMHO)

I usually take the daylight flight 90 ORD LHR but sometimes, in the middle of summer, I take the DFW-LGW nonstop and try for 2 or 3 on the "A" side. Something fascinating about looking across the top of the world at the daylight that is "tomorrow".

Best Lav: The HUGE (we are talking airplane relative terms here) Lav on starboard side, just aft of boarding door. Its technically in Biz cabin but nobody has ever said a word. You could hold a small meeing in there....I havent but you could.