The only issues I have with the 42PFL9664's pictures, in fact, are mostly familiar ones. First, black levels drop off quite considerably if you have to watch the TV from a wide-ish viewing angle.
Second, with the HD Natural Motion system engaged, areas of very fine detail can occasionally flicker a touch, and small, fast-moving objects like cricket balls can appear with noticeable ghost balls following behind them. Both these issues are to do with the scanning backlight, though, and so if you find a certain source to be particularly affected you can sort things out by just turning the Natural Motion (and thus 200Hz) processing elements off.
Following on from this last point, it's true with the 42PFL9664 as it is with so many other Philips TVs that in order to consistently get the very best from it, you do need to regularly adjust some of the set's processing elements. In other words, you have to be more proactive than you might ideally like to be. For instance, as well as deactivating the HD Natural Motion system for sport, for god's sake make sure you use the provided Game mode when playing console games, for otherwise the delays in producing the picture caused by the TV's huge processing engine will lead to your face being shot off on Call Of Duty with terrifying regularity.
As I always point out, though, for me the key point in all this is that the picture quality reward for your time and effort is exceptionally high.
One final negative point I might add here is that the 42PFL9664's pictures aren't the brightest when calibrated to deliver the best colour and black level response. But this shouldn't be a major issue in a normal living room environment - and you can certainly make the picture much brighter if you're willing to forego a little black level response and colour neutrality.
Most flat TVs struggle to produce a convincing soundstage to accompany their pictures. But despite its puny 49mm depth, thanks to a combination of two integrated subwoofers and two dome tweeters the 42PFL9664 actually sounds remarkably powerful. It can hit genuinely cinematic volume levels without distorting, it's very effective at reproducing the sort of subtle treble details that give a sound mix a sense of life and space, and most striking of all, it delivers some really quite deep and potent bass. In fact, the bass can occasionally sound a touch overwhelming if you don't rein it in via the sound adjustment menus. But I'd give my right arm to be faced with a similar 'problem' with more rival flat TVs!
While I might have only been partially convinced by Philips' attempt to do 'mid-range' last week, the 42PFL9664 continues to show that when the brand is in flagship, no-holds-barred mode, it's very much still an innovative, original and lovably eccentric TV force to be reckoned with.