I'll take one!
I've actually been able to spend quite a bit of time with the giant Panasonic 103" plasma, as my local AV high-end store has been displaying it in a dedicated room (which until recently housed the projectors they sold) for several weeks. Both the Panasonic and the store salesmen have been great about letting me have a go at the display, putting it through paces with various material. I've watched some Blue Ray (Kingdom Of Heaven, Ice Age 2, Superman Returns, Fantastic Four), some SD DVDs, a variety of broadcast HD etc over a couple weeks. (Man it's indulgent, the thing is set up in it's own room, nice and light controlled, and often I've been able to be just alone, sitting there, drinking it in).
It is truly an awesome display! People are usually just shocked when they walk into the room and see this thing playing - even before they know what they are looking at. (Most people don't know what it is, because it's in a fairly dark room, so they first say something like "Oh My God, that looks amazing! What is it?")
And I can also see why people who are really into front projection would still prefer a projector. That is, especially if you are really into trying to re-create the projected film look, you just aren't going to do that more accurately than using essentially the same approach as projected film. So nothing feels more like "being at the theater" than a front projected image (in a big enough size).
Further, the best front projectors in really light controlled rooms will give you even deeper blacks than this plasma. Because I'm deciding between the new Panasonic 65" 1080p plasma and a front projector, my projector demoing has ratcheted up in earnest (an ongoing interest over the years, as front projection and plasma are my two favorite display technologies). I just viewed the new Sharp projector (that Greg Rogers raved about has having the highest simultaneous contrast he'd ever experienced) and it was incredible. It also had deeper black levels - evident more in "torture test" lower contrast scenes especially - than this giant Panasonic. As well, the Sharp may have been even as sharp (or sharper!) than the Panasonic in some scenes.
All that said, a plasma this size just provides a different experience. It does, effortlessly, what excite many people about upgrades on their projectors - that is provide that extra dynamics, that more life-like intensity and palpability and depth.
In comparing plasma with practically every other competing technology what I find distinguishes plasma is not only the high light output (and perfect geometry etc), and excellent ANSI contrast -- it's the "palpability" factor. The images on a good plasma have a "solidity" to them, a reach-in-and-touch-it factor, that I just don't quite get from front projection. Because front projection, even really bright front projection, still strikes me as what it is "light projected on a screen." And the blacks on front projection, no matter how dark, still look like "shadows on a screen." On projection devices (both rear and front) bright areas tend to remind me I'm seeing a screen with a bright light on it.
But the plasma light is just directly emitted. There is nothing "behind" the light to see, as it were, so the image never has a phantom-like or see-through quality. This, combined with the more life-like brightness and often convincing ANSI contrast makes plasma give more of a "window-on-reality" look, I find, with the best material.
So all that said, that is what I found the Panny 103" plasma did for images. It was the "plasma effect" but a front projection size. And that is what could make it so jaw dropping. When I saw the first scene in Ice Age 2 (Blu Ray) the camera soars slowly past glacier cliffs to find a character climbing an ice wall. The impression of going "around" solid-looking cliff walls was unlike I had ever seen from any projection device.
The whole landscape took on a more "I could walk right into" feeling, and the image in general just brought the characters and their world more alive than any projection I've seen.
Likewise with the live-action movies. Kingdom Of Heaven (Blu Ray) just looked incredible! And it wasn't an overly contrasty presentation of the image, as I see from some plasmas. The subtlety of color, shading, contrast, shadows was really amazing - very film-like. Yet the images stepped also into that solidity and realism that plasma does so well. Lots of people were coming through the room each time I viewed that movie and everyone was slack-jawed. All the projector salesmen said, as good as they thought their projectors were, nothing impressed like that huge Panasonic.
Fantastic Four (Blu Ray) was also you-are-there movie-geek nirvana. In fact, I think Panasonic had to really go to town in perfecting the processing for a plasma this large because one of the most amazing things about it is how little noise there is in the image. I mean...there was virtually NO noise in lots of the material I watched on the display - I've seen significantly more video noise on projectors, smaller plasmas and lots of RPTVs.
So yeah, I sure wouldn't kick this baby outta bed!
The only thing for me, being a black level fiend, is that the tougher-to-render low contrast or very dark scenes tend to show the shortcomings of this 1080p panel.
This first crop of 1080p plasmas (from Panasonic AND Pioneer) have apparently had to take a slight hit on black levels, because in order to achieve near the same relative brightness as the lower res models, the pixels of the 1080p models need a slightly higher "idle" charge (which keeps them from going blacker). So I could want some deeper black than I saw when I spun my torture-test BladeRunner SD DVD on the Panny.
But all in all, this display does deliver an effect that is mesmerizing, and different, from projection.