Do all the non-bulkhead MCE seats have the same leg room? We're on a 10 hour daytime FRA-CLT in economy looking to spend the ~$100 for some extra space. I figure the $10 an hour is worth it. I'm not sure I want to sacrifice the seat width for the tray table in armrest of the row 17 seats (the AB and KL are gone but the middle is open). I've availability in row 20 aisle in the mid section or 27 by the window. Is there any difference in these seats? Seatguru doesn't say anything about any difference.