Our original review continues below:

The fight for the ultimate OLED TV in 2019 is already raging between LG and Panasonic, but now a new challenger approaches: the Sony AG9 replaces last year's award-winning AF9 as the Japanese brand's flagship OLED TV.

The AG9 has a fine reputation to uphold, and not least because the AF9 confidently secured Expert Reviews’ TV of the Year award in 2018, but on this showing, Sony may need to buy a bigger awards cabinet. The AG9 is what is known in the business as ‘a bit of alright’.

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Sony AG9 review: What you need to know

Just like last year’s models, the BRAVIA AG9 is part of Sony’s Master Series. This means that it’s designed to mimic the quality and colour accuracy of Sony's own BVM-X300 reference mastering monitor – a monitor which has graced many a Hollywood movie production suite.

In addition to the 55in KD-55AG9 and the 65in KD-65AG9 which we’re reviewing here, the AG9 will also be available in a massive 77in screen size. Just don’t ask how much it’s going to cost. (It’s £6,999.)

Features on the Sony AG9 include a 4K OLED panel, the company's top-end X1 Ultimate video processor and the ingenious Acoustic Surface Audio Plus technology which turns the entire screen into a giant speaker.

The Smart TV platform runs on Android Oreo 8.0 and offers HDR-enabled versions of all the essential video-on-demand apps such as Netflix, Amazon Prime Video and Youtube. Freeview Play makes the grade, too, and provides access to all the major UK catch-up TV services including BBC iPlayer.

The AG9 supports HDR10, HLG and Dolby Vision. HDR10+ is absent however.

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Sony AG9 review: Price and competition

The OLED marketplace is getting pretty crowded, but with a street price of £3,799 at the time of publication in August 2019, the Sony KD-65AG9 comes in straight at the top-end. Only Panasonic's flagship £4,299 TX-65GZ2000 costs more.

The Sony AG9 is flanked by a troop of cheaper competitors. The 65in LG C9 (£2,999) and E9 (£3,499) both offer full HDMI 2.1 support for less cash, and Panasonic's superb step-down GZ950 (£2,499) and GZ1500 (£2,999) models are equally tempting.

Sony AG9 review: Design and connections

This is a fine-looking TV. The Sony KD-65AG9 sits almost vertically – there’s a slight relaxed backwards lean – and the extremely low-profile stand doesn't take up much space at all. A discreet Sony logo adorns the bottom left corner of the bezel. As OLED TVs don’t need a separate backlight, Sony has taken full advantage, paring the AG9’s body and bezel down to a mere sliver.

All the various connections are found on the left rear of the TV. There are four full-bandwidth HDMI 2.0b ports, all of which are HDCP 2.3 compliant. The pair of spring clip terminals the rear reveal one of the AG9’s neatest party tricks: you can connect the AG9’s Acoustic Surface Audio Plus speakers directly to a home cinema amp and use it as a centre channel.

Sadly, the only HDMI 2.1 feature implemented on the Sony AG9 is enhanced Audio Return Channel (eARC) on the HDMI 3 input, and you will have to go into the user menu to enable it specifically. We tested eARC using a Denon X3500 receiver, and it works well, passing Dolby TrueHD Atmos soundtrack from 4K Blu-rays through the TV's HDMI 3 port.

Compared with last year's AF9, the onboard Acoustic Surface Audio Plus system has been changed from 3.2 to 2.2 channels, consisting of two actuators and two subwoofers at the back. This is partly to achieve a slimmer design for flush wall-mounting, but we don't think there's any significant drop in sound quality. The Sony AG9 remains one of the best-sounding TVs – if not the best – on the market, with outstanding clarity and sufficiently weighty bass. A feat made all the more impressive by the fact that there's no visible exterior speakers to be seen.

You might be slightly disappointed to hear it, but the AG9’s premium remote control is probably the biggest upgrade on the outgoing AF9. With an ergonomic shape and excellent tactile feedback working in tandem with the super-responsive Android TV system, it makes the AG9 an absolute joy to use.

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Sony AG9 review: Picture quality & gaming responsiveness

All OLED TVs can produce perfect blacks – the technology makes it possible to turn every pixel on and off independently – but it's the shades of colour just above black that have proven challenging for various TV manufacturers to render in an artefact-free manner. Sony OLEDs generally suppress the telltale noise and artefacts better than most other TV brands, and it’s pleasing to find that the same applies to the AG9. It’s still not perfect, though: when watched in a pitch-black room, our review sample exhibited very rare instances of flashing artefacts in heavily compressed dark scenes.

After calibration, colour accuracy was excellent on our Bravia AG9 review unit, translating to natural and realistic colours and lifelike skin tones. Brightness uniformity was incredibly clean when checked with full-field grey slides, with no sign of banding, dirty screen effect (DSE) or colour tinting, meaning that you can watch sports and play games without being distracted by such issues.

Our review sample exhibited some vignetting when displaying full-field slides just above black, particularly so on the left side of the screen, and this caused some minor shadow detail loss from the extreme left edge of the picture in very dark scenes. As with any TV from any brand, there is an element of a lottery to the buying process: some TVs, even of the same model from the same manufacturer, will always be better than others due to variances in the panels.

While uniformity can vary from one unit to another, what you can take to the bank is Sony's class-leading motion and video processing. Even with Motionflow disabled, slow panning shots in 24fps movies – in both SDR and HDR – are handled smoothly without any sign of judder. And should you choose to engage motion interpolation, Sony's technology is less likely to incur interpolation artefacts than other brands. Meanwhile, the upscaling capability of the X1 Ultimate processor is fantastic, retrieving sharp detail from sub-4K content without excessive ringing or fizziness. It’s equally pleasing to see that gradients were rendered smoother than many other OLEDs even without the help of Sony’s Smooth Gradation feature.

For HDR content, the AG9’s DCI-P3 colour gamut coverage came in at 98%, while peak brightness measured 530 nits on a 10% window after calibration, and 135 nits full-field. Those figures are relatively low, but the Sony AG9 is equipped with dynamic tone-mapping which analyses the picture on the fly to make each scene look as bright as it needs to be, all the while keeping an eye on accuracy. During playback of real-world HDR10 content, the Sony AG9 doesn't look dim at all in a side-by-side comparison with a 2019 OLED with a measured peak brightness of 700 nits.

Turning our attention to other HDR formats, we watched Wimbledon in HLG HDR through the TV's internal BBC iPlayer app, and it certainly looked good. Sony currently don't have any plan to support HDR10+ on their televisions, but we don't think this is a deal-breaker since HDR10+ dynamic metadata is designed to mainly help low-end to midrange TVs.

Dolby Vision content on the Sony AG9 still looked a bit darker than on an LG OLED, and this is due to the low-latency Dolby Vision profile that the Japanese manufacturer uses. Speaking from experience, the best Dolby Vision picture quality is still provided by LG (and now Panasonic) OLEDs. On Sony OLEDs, we actually prefer to watch in vanilla HDR10, especially with the dynamic tone-mapping on X1 Ultimate sets.

For gaming, input lag measured 26ms in both 1080p SDR and 4K HDR Game modes, and while this figure is probably responsive enough for all but the most hardcore twitch gamers, it's the absence of HDMI 2.1 gaming features such as ALLM (Auto Low-Latency Mode) and VRR (Variable Refresh Rate) that will steer gamers towards rival TVs from LG and Samsung. Top tip: To get your Xbox One X and PS4 Pro to send 4K 60Hz HDR video signals to the Sony AG9, you'll need to venture into the TV's user menu, and change HDMI Signal Format from Standard to Enhanced.

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Sony KD-65AG9 review: Verdict

The Sony AG9 produces by and large the same excellent picture quality as the AF9 – in fact, it’s so similar that we’d say the premium remote control is the biggest upgrade here. That’s no insult however: there was precious little room for improvement. Thanks to its stunning colour accuracy and class-leading motion and video processing, the Sony KD-65AG9 stakes its claim as one of the best OLED TVs you can buy today.