I would love to know if they are the same seat I sat on a flight from LAX to PHL last nite, #AA520. The seating looked new, in fact i thought it was newer plane but the flight attendant told me it wasn't. This was an A321 aircraft. I have flown this plane probably 300 times or more and never had a complaint. It was the most uncomfortable airplane seat I have ever sat in. My back is actually hurting me. It also felt as though there was less seat padding as well. I'm wondering if it's one of those seat types that are designed to enable airlines to jam in another row or two.