If you are looking for the ultimate Sony Xperia XZ2, then you may want to look to import it from Asia. Sony Mobile is adding 6GB RAM to the Hong Kong and Taiwan variants (H8296), versus 4GB seen elsewhere globally. We're not entirely sure why Sony couldn't add 6GB RAM for everyone, but if you want the best-specced version of the Xperia XZ2 you should browse eBay for Taiwanese/Hong Kong listings in March, when the phone is expected to launch.
New firmware released for Xperia XZ Premium, XZ1 and XZ1 Compact with Jan 2018 patches
Xperia XZ Premium joins Sony’s Open Device Program
Xperia XZ Dual announced for India; pre-orders open 1 October
Xperia XZs pitted against Galaxy S8+ in low light video test