As promised, Sony has pushed out the last Concept build to participating Xperia X units. The update brings along Android security fixes May and some functionality changes. The update features improvements to low memory stability. Some fixes are also included, such as faster GPS fix and charging LED bug fix. Currently, those on the the Experimental track are getting the update, but stable track should also get it soon. Via
Source: http://www.gsmarena.com/last_concept_build_for_sony_xperia_x_brings_may_security_patch_other_changes-news-24908.php
