Sony Xperia Z1 was released in September 2013. Xperia Z1 is powered by a Qualcomm Snapdragon 800 2.2GHz quad-core processor, and 2GB of RAM. The 5″ TFT display has a resolution of 1920 x 1080 and is manufactured utlising Sony’s Bravia technology. Internal storage comes in at 16GB, with a further 64GB available with microSD. Z1 has a 20.7MP sensor.
Sony Xperia Z1 can be updated to Android 6.0 using AOSP ROM. It is as good as stock Android and it will offer better features and performance than Xperia UI. If you want to install this ROM, a detailed guide is given below.