The screen is highly responsive and compatible with stylus as well as regular pencils or metal pens. Being waterproof means that users can use the phablet in the rain, or take it to the pool or beach. Although lacking a rear LED flash, the phone's cameras are capable of taking pictures/videos at any light. The Xperia Z Ultra was originally shipped with Sony's custom version of Android 4.2.2, and as of 27 June 2014, the Xperia Z Ultra has received the Android 4.4.4 (KitKat) update. In addition to Sony's own applications like Walkman, PlayStation Mobile, battery stamina mode, several Google apps also come preloaded (Google Chrome, Google Play, Google Voice Search, Google Maps, NeoReader™ barcode scanner). On 2 November 2014, the Xperia Z Ultra Google Play Edition received an update to Android 5.0 Lollipop. On 4 December 2015, the international version of the Xperia Z Ultra received the Android 5.1.1 update from Sony. Because of its size, the phone's on-screen keyboard and dialer can be switched to either sides for users to easily reach all keys with only the thumb. For gaming, DualShock 3 is natively supported. C6843 variant with 1seg TV tuner is sold in Brazil. All variants (except SOL24) support four 2G GSM bands 850/900/1800/1900 and five 3G UMTS band 850/900/1700/1900/2100. Sony Xperia Z Ultra is praised for its "very classy" exterior, "stunning" massive Triluminos display, stylish premium design, slim form, light weight, impressive build quality, durability (water and dustproof), interesting pencil/pen compatibility, and powerful specs. CNET's editor Aloysius Low wrote that "Sony has set a very high benchmark with the Xperia Z Ultra", challenging the leadership position in the phablet market. PhoneArena wrote that the Xperia Z Ultra is "an engineering marvel" "towering above all other phablets not only in screen size, but also in specs and design". Its performance is described as "blazing fast", claimed to be the "fastest mobile device they've tested so far" (as of 13 August 2013). According to ExpertReviews, the Xperia Z Ultra is "more than twice as fast as a Galaxy S4".