Why you can trust TechRadar We spend hours testing every product or service we review, so you can be sure you’re buying the best. Find out more about how we test.
The Sony KDL-40NX723 grants you access to Sony's Bravia Internet Video portal, and with built-in Wi-Fi on board it's easier than ever to get online.
Bravia Internet Video offers a fantastic range of sites to choose from. These include catch-up TV services such as BBC iPlayer, Demand 5, Sky News and Eurosport, video on-demand such as YouTube, LoveFilm, Qriocity and Dailymotion, plus a range of lesser-known European and specialist sites, a channel dedicated to 3D clips and Sony Entertainment TV.
That's still the best range of content found on any connected TV.
But there's more than just videos to keep you entertained. You get a Music Unlimited service courtesy of Qriocity, plus apps for Facebook and Twitter that enable you to keep on top of your social networking without the need to fire up a laptop.
The built-in Skype functionality enables you to make free video calls from the comfort of your armchair, provided you fork out around £80 for the CMU-BR100 voice control camera and microphone.
You can also look up details about the content you're listening to or watching, thanks to the Track ID feature.
And to top it all off there's an Opera internet browser that enables you to visit any website you like. You're at the mercy of the remote, however, which makes it a time-consuming process, while the lack of support for embedded video is a big limitation.
These extensive web features are backed up by DLNA media streaming, which allows you to access content stored on PCs, phones and other devices.
Thanks to the Wi-Fi Direct support you can hook up the TV to other devices without getting any routers or cables involved. And with the relevant free app installed on your smartphone, you can use your mobile phone as a TV remote control or as a second screen for online video – plus it can act as a keyboard when browsing the web.
But let's not forget that this is a TV we're talking about, so let's turn our attention to the picture tech.
It's powered by Sony's X-Reality processing engine (new for 2011) and features MotionFlow XR200 processing, which confusingly isn't 200Hz but 100Hz, inserting new transitional frames between the existing 50Hz image to improve the smoothness of movement.
The smart TV set also features a whole host of image optimisation tools that you could spend all day playing with. Sensibly, Sony has separated the more basic tweaks such as colour, contrast and brightness into the first page, with a separate Advanced Menu at the bottom.
Here you'll find Black Corrector, Gamma, Live Colour and Advanced Contrast Enhancer, Clear White, White Balance, Edge and Detail Enhancers and more. Picture pedants will definitely get their money's worth.
Naturally at this price, the Sony KDL-40NX723 is also 3D-compatible with a built-in IR emitter. But you don't get any glasses in the box, and at around £60 a pop that'll soon add up if you want to kit the whole family out. There's a simulated 3D mode on board though, so you can give any 2D content you're watching a 3D effect.
Freeview functionality is excellent. As well as picking up HD channels, it offers a comprehensive electronic programme guide (EPG). And if you connect an external HDD with 32GB-2TB capacity to one of the USB ports, you can even record TV programmes.
Finally – and perhaps most cleverly – the 40-inch TV has a built-in camera sensor with face recognition software, which activates certain functions automatically depending on your position in the room. The Presence Sensor will darken or turn off the picture if it can't detect anyone in the room, while the Distance Sensor aims to stop kids getting square eyes by sounding an alarm if they get within 1m of the screen.
Meanwhile, Position Control registers where people are sitting and adjusts the volume balance between the left and right speakers, as well as optimising the picture.
All of these modes can be activated in the set-up menu, and when doing so it shows you what the camera sees – complete with white squares clamped around the detected faces – and a grid indicating your position.
With all this smart technology inside, the Sony KDL-40NX723 makes you feel more and more like you're in Back To The Future Part 2 – next year expect hover boards and holograms.
