I quote from the What Hi-Fi review:
Local LED dimming
But Philips asserts its so-called LED Pro technology compensates by delivering the best possible picture, because it allows for independent local dimming of segments of the LED panel as the image dictates, leading to significantly better contrast.
It also ensures superior backlight uniformity: LCD TVs can suffer from 'hot spotting', where light is brighter towards the centre of the screen and dimmer on the edges, but a full-array LED panel has uniform light output throughout.
The result, claims Philips, is a formidable 5,000,000:1 dynamic contrast ratio....
As you'd expect from a Philips, it's laden with picture processing technology too: thanks to the powerful Perfect Pixel HD engine, upscaling is excellent with Freeview broadcasts, the '9704 working hard to cut down digital block noise and other off-air undesirables.
Simply sensational images
Motion-handling with Blu-ray is exceptional too ... and the fast 1ms panel response time, enabled by 200Hz Clear LCD technology, ensures minimal smearing and motion blur ...
As for the biggest selling point of all - contrast performance - it's just as fabulous as you'd hope it would be, the Philips generating pictures that get close to the dramatic depth and punch of Pioneer's remarkable (and now unavailable) Kuro plasmas. [bolded by hnery]
... and Philips' remarkable Ambilight Spectra 3 system (which projects lights from both the sides and the top of the TV to enhance your viewing) and you've a complete TV. The Philips 40PFL9704 isn't cheap - but it is wonderful. ...
I agree with every word. The picture is sensational !