One thing about the SQ J seats, I have not noticed the wear and tear to the extent others have, but one thing I will note when I was ejected from row 11 to the back of the upper deck by someone who claimed my allocated seat, as discussed elsewhere, I noticed the seat (in row 90something) in much better condition. I think the seats towards the back are always in better condition, because they are probably always the last to be allocated and therefore only used half the time .... food for thought 
