So I've owned the Xperia X before but I've never had the opportunity to purchase the X Performance before until tonight when I found a good deal on one. Can anyone give me any advice and feedback on this device?  How is it compared to the regular Xperia X?  I know it runs a 820 processor which should make it far superior to the regular X. Does anyone know how to flash the European firmware on the US version to enable the fingerprint sensor?  Any advice and feedback would be appreciated. Thanks.