One final massive strength of the P54Z1 that suddenly explodes into your consciousness with Blu-ray playback is its black level response. For while I'd felt strangely unmoved by this aspect of the TV's pictures with standard def, with a good Blu-ray film I'm suddenly seeing black levels deeper and more tonally neutral than anything Panasonic has managed before (except for the P46Z1!).
By tonally neutral, by the way, I mean black colours are hardly infused at all with the slightly green flavour noted with some screens lower down Panasonic's plasma hierarchy.
To sum all this high definition glory up, I'd say that the P54Z1 produces the most cinematic pictures we've seen since Pioneer's KURO TVs - and you can't say fairer than that. Especially when you consider that the quality we're describing is coming via a wireless AV delivery system.
The fairly hefty 'bolt-on' speakers Panasonic does with the P54Z1, meanwhile, work hard to ensure that the blissful Blu-ray film experience is joined by some tip-top audio. The audio from a good film mix fills even a large room, without sounding harsh, imprecise or muddy, while dialogue sounds clean and real. There's even a reasonable amount of bass to be heard, and that's certainly not something you get with your average super-slim TV.
Another day, another TV that's got me feeling conflicted.
Having finished my testing with a few Blu-ray discs, I'm still basking in the warm glow of the P54Z1's truly exceptional HD movie performance. And yes, I've been at least a bit seduced by the extraordinarily skinny design and extremely effective WirelessHD technology.
But forcing myself into a more sober reflection on my experience with the P54Z1 as a whole recalls those sometimes underwhelming standard definition images - which look slightly worse than they did on the P46Z1 because of the P54Z1's extra screen size. And then there's that £4,500 price tag to consider. This is a price so high, of course, that it actually makes the now £2,500-odd asking price of Pioneer's 50in KRP-500A look cheap. And while the Panasonic arguably matches that legendary Pioneer with Blu-ray playback, the Pioneer is for me a more consistent picture all-rounder.
So unless you're desperate for the Panasonic's extra 4in of pictures, slim/metallic design or wireless technology, the Pioneer is arguably the more sensible buy. If you can get hold of one before they disappear forever, of course…