Well, if you can still find an IN83 (now discontinued), you will get a brighter projector with superior color, and seriously inferior black levels. The IN83 was several times the price, and when it comes to color accuracy, and skin tones, it's about the best I've seen. The Panasonic, while very good at color, is, in the grand scheme of things, no match.
That said, the IN83's black levels are NOT impressive, not even if it was a $2500 projector. I love the IN83, and I'd buy it over the Panasonic if they were the last two projectors on earth, but I would never consider the IN83 without pairing it with a serious High Contrast gray surface, as the black levels need all the help they can get.
As to the SP8602, the original engineering sample was so limited that I couldn't even calibrate it. Yet, it looked really good, razor sharp, etc. And it has a dynamic iris, unlike the IN83. From my quick look, it's probably very close to the PT-AE4000 in black levels. Certainly they are in the same class. Generally, the Panasonic is as least as good as the new DLP's sporting dynamic irises. That said, I don't expect there to be enough black level performance difference between the two for that to be a decision factor.
I have great hopes that the SP8602 will be one of the best projectors out there, and am pretty certain it will be, overall, a full step up over the PT-AE4000. It will be more at home competing with the JVC RS15 and RS25 (mostly the 25), the Sony VW85, Planar PD8150, etc.
Panasonic PT-AE4000 vs. Panasonic PT-AE3000
Ahh, this is easy. The PT-AE4000 costs less, and is slighty improved over the AE3000. In my opinion the single greatest improvement is in "best mode" brightness. Unless you need that boost, though, I can't see anyone trading up from a PT-AE3000 to the PT-AE4000, from a value standpoint. Yes, you would also get slightly better blacks, but if that's what you are after, I'd say wait, or go to a different projector that has better blacks still (JVC - pick one, or an Epson UB...)
Panasonic PT-AE4000 vs. JVC DLA-RS25, DLA-RS15 older models
Forgetting the Lens Memory aspects, this is a case of very good projector vs. great projector, and amazing projector.
Consider the PT-AE4000 a poor mans JVC DLA-RS10, RS15 projector. It can't match the black performance of the RS10, even with it's dynamic iris.
They both have 2:1 zooms, lens shift (the Panny has more), both lenses are motorized (although the PT-AE4000's lens shift is manual.
Colors, Panasonic while most impressive is definitely not a match for the RS20/RS25. I would suspect the same is true compared to the RS15, but to a lesser degree. Haven't reviewed that one yet, but the older RS10 didn't have quite as sophisticated a color management system as the RS20, so you can't dial in quite as well.
It's a case of two grand vs $4000 or more, and $8,000 for the RS25.
And of couse, all the JVC's (the old RS2 excepted) are at least 50% brighter in "best" mode, while being only about 90% as bright in "brightest" mode.
Panasonic PT-AE4000 vs. Sony VPL-HW15
Hmm, a very tough call. My first thought on the subject, is that specific features notwithstanding, I like the Sony better than the Panasonic, but probably not by $800 more.
That said, brightness is going to be an important determining factor. Starting with brightness. The Sony has about a 100 lumen advantage (538 to 430) in "best" mode. That may be a key factor for many who are primarily movie people, or who want a largish screen.
The Sony though, can't match the "brightest" mode, with a not really bad, but way too cool Dynamiic mode (9000K color temp), that's real thin on reds. The HW15 can do about 840 lumens pushed to the limit, and the picture with that setup is no match for the Panasonic's Dynamic mode with 930 lumens calibrated. Worse for Sony, to get very good color out of a "brightest" mode, we never were able to get more than about 670 lumens. The Sony, in other words isn't going to be high on the list for anyone who wants to watch sports or TV / HDTV with the room intentionally not fully darkened. (I know I don't like watching sports with friends with my room fully darkened!
The PT-AE4000 has CFI, the Sony saves CFI for their more expensive VW85 which we hope to review soon (12/09).
I will give the color accuracy, or rather specifically, skin tone handling advantage to the Sony. it's Sony's thing, and they do have really good skin tones. I don't think any of the 3LCD competition can quite match the Sony in regards to skin tones, although all of them do very respectable jobs.
The PT-AE4000 has a slight advantage in placement flexibility with a longer range zoom lens, and more lens shift. Sharpness is very close but the advantage goes to Sony.
Let's just say the Sony is a touch more refined. The Panasonic more feature laden, but once you've determined that they can both work in your room, I'd say next consider the lumens issue. I think, beyond the dollar difference, it will be the determining factor for most, so what you watch, and how, will help you decide.
