i'm flying a 777 (BNE - DXB) than onto an A380 (DXB - LHR) in a few months in economy and i'm thinking of paying for preferred seat - on the 777 i'm thinking rows 17 to 21 (in the little front cabin) and on the A380 i'm thinking row 41 (2nd row of ecconomy). is there any downside to this?