Would also recommend you look at seatguru, but my tip would be get as close to the front of economy as you can as the plane usually empties from the front, and the sooner you are off, the shorter the immigration queue.
Also, being just behind Premium Economy sometimes means if there is a big queue for the economy toilets, there is quite easy access to the toilets at the rear of Club class. Came in quite handy when I was pregnant and caught short!