We fly the XM'd 767 pods often , and as a couple prefer the "A" seats mid cabin.....say3,4 A
The traffic is less so to the Lav.....as it is just usually the couple of folks directly behind you.
The seats/pods are actually not as angled as they appear on the seat map chart. They are rather forward facing.
I don't agree with the last row in J as potentially quiet. There has been many a flight when there have been some wee ones in the first row in Y....in some distress. A few rows into the J cabin provides a bit of a buffer.
ALWAYS brings ear plugs regardless of seating. They can block out the drone of the engines....even if everyone is mute around you.