Sony Xperia U FAQ
The Xperia U has 8GB of built-in flash memory, and is not internally expandable. Of that, 4GB is available via USB (MTP protocol) for music, video, images etc. 2GB is reserved for phone storage, such as text messages and some applications - many applications are able also to use the main 4GB area. The remaining 2GB is hidden and used exclusively by the Android operating system. So the total memory available to users is 6GB, though only 4GB of that is directly accessible. Mentions of 56GB refer to the availability of an additional 50GB free on-line "cloud" storage.
This information is wrong, but widely spread, and appears to have been based on Sony's own testing of an early prototype. The production Xperia U's SAR as measured by the FCC is a maximum of 1.09W/kg, well within the legal limits for the USA. The SAR as used in most of the rest of the world, which is slightly differently measured, is 1.22W/kg, again well within the (higher) legal limit. If the phone was over the limit, it would be illegal to sell, but still not dangerous under normal circumstances since safety margins are designed into the limits.
The iPhone (prior to the iPhone 5) featured a screen with a 3:2 aspect ratio (the proportion between vertical and horizontal), whereas the Xperia U, in common with most Sony smartphones, features a 16:9 ratio screen. Screen size is measured diagonally, so a 16:9 screen of 3.5" will be narrower but taller than one of 3:2 ratio. The overall screen area will be slightly smaller, but only by about 7%. Widescreen format video will however play back with a larger picture on the Xperia U, since it is better matched to the 16:9 screen ratio.
The battery supplied is a Sony BA600 of labelled capacity 1290mAh. Some published specifications refer to the capacity as 1320mAh, however this is specified as the "typical" capacity, whereas 1290mAh is the "minimum" capacity as new, to allow for tolerances in the manufacturing process. They both refer to exactly the same battery, just different ways of expressing its capacity.
This depends heavily on your usage patterns, options you have enabled, and mobile/wi-fi signal strength. With low to moderate usage and good conditions, standby times of 2 to 3 days are very possible, however many people report significantly shorter times. A particular consumer of battery is borderline mobile reception, so if in a poor 3G reception area it may be better to keep the phone in 2G mode and only switch to 3G for data when absolutely necessary.
3G video calling is a network specific function, and not supported on the Xperia U. However Skype and other preinstalled and downloadable applications allow video calling via the secondary front-facing camera to others with compatible software installed on their phone, laptop or desktop.
Almost certainly not. It's not mentioned in the user guide, but for protection during transit the Xperia U is shipped with a small piece of transparent plastic film over the lens, which seriously impacts image quality especially when using the LED "flash". Remove the back of the phone, and pull the plastic film off via a small tab. In some circumstances the LED can still be a little overpowering; some people get better results by adjusting the exposure compensation slightly. When operating properly and unimpeded, the image quality from the camera is very good.
As of November 2012, ICS (Android 4.0.4, build 6.1.1.B.1.10) is now being rolled out to Xperia U phones. However it is a phased release, being made available to batches of phones at a time. Check under the battery for an eight-digit number (e.g. 1234-5678) - this is your SI number. Google for it, and you may find more information about if and when the upgrade will be available if it is not already. Note that unlike minor Gingerbread updates, you will not be alerted on your phone when the ICS upgrade is available, and you cannot upgrade over-the-air to your phone. To be absolutely sure of the upgrade availability, and to download and apply it, you must use the Sony Update Service or PC Companion software on your desktop or laptop.
Whether ICS would be a recommendable upgrade is a little more questionable, since the Xperia U is a little low on memory especially with all Sony's extras, so performance is likely to be a little sluggish. If you choose not to upgrade, Android 2.3.7 build 6.0.B.1.564 is generally held to be the most stable and recommended Gingerbread version and should continue to work fine.
Ice Cream Sandwich (ICS, Android 4.0.4) is good in parts, but not an overwhelmingly worthwhile upgrade. As anticipated, it is likely to make your phone a little less responsive, since its memory demands are greater and 512MB is borderline for ICS's system requirements. Good features include the new Google Chrome browser, being able to reject incoming calls with a preset text message, and its new power management option to disable data while sleeping which can dramatically extend standby battery life. Not so good "features" include SMS previews etc not being visible on Sony's custom lockscreens (the stock ICS lockscreen is not available), the LED message indicator no longer flashing unless power is plugged in, the new Album app being rough round the edges, 802.11n wi-fi reception being unstable, and the camera being lethargic and buggy.
Note that for best experience, we would recommend doing a clean upgrade if possible. As others are reporting, performance and responsiveness seem noticeably improved for later doing a factory reset. Furthermore, having carried out a reset, features such as the "Media" button on the home screen work properly, which was not the case after the original non-clean upgrade which deleted Gingerbread's photo gallery link without replacing it with the new Album app.
An over-the-air minor update 6.1.1.C.1.10 is believed to address some of the issues with ICS, and is being rolled out to upgraded handsets during December 2012.
Sony have now stated that Android 4.1 will not be released for Xperia U and several other lower specified phones from the 2012 range. There are reports of an OTA update being rolled out in December 2012, but this is not Jelly Bean but a maintenance update for Ice Cream Sandwich. Rumours had been rife after an Italian Sony representative posted a comment on Facebook whose translation suggested the contrary, but this proved unsubstantiated.
The Xperia U does have 512MB, however parts of this are reserved for various functions of the phone, so we don't get to see the whole lot. Depending which application or system options are used to display the maximum available memory, the number may vary between about 290MB and 376MB. Note that free memory being very low (sometimes only a few MB) is not necessarily a problem, due to the efficient way the Linux system Android runs via manages memory.
Yes, the Screen Filter app from Google Play can control what it refers to as the "soft-key backlight", however it's not a perfect solution since the app has to be specifically run and keeps an icon in the notifications area, and there are still a few instances the bar lights up that it cannot regulate. However it should be noted that the bar is nowhere near as intrusive in practice as one might imagine.
From the speaker it's good but not brilliant, and a little on the quiet side. The difference the xLoud technology makes is questionable. Through high quality headphones the Xperia U sounds pretty good. Unfortunately the hands-free headset typically supplied is of rather average quality. The socket works with any 3.5mm headphones, and CTIA handsfree sets.
Read the specs and the reviews and make your own decision, you lazy wotsit.