I was on a 787-10 yesterday, I was in 11L, odd number, window, second cabin of Polaris. If you have an even numbered seat people tend to hit you while walking by, the odd numbers give much much more privacy.

I found 11L on the 787 to be very very noisy, you're right next to the engine (where as on the 777 the engine is farther behind you).

In general I prefer the rear of the front cabin, but anything beats sitting in the far back.