Perhaps the biggest downside to the HD4000 as a bright projector for home theater is that it could be brighter still. While it will meet the needs of many people who need to do at least some watching with more than minimal light in the room, there's an old saying of sorts - you can never have too many lumens. I believe there is a definite market for bright widescreen projectors for home offering 3000 even 5000 lumens. (Of course they will need "theater modes" so their brightness can be lowered for nighttime/dark room viewing.) The HD4000 in low power cinema and video modes is suitable for dark rooms, although if the screen is too small, some may find the HD4000 overly bright. In folllowing some of various a/v forum threads, I have read of those who are affected by the rainbow effect when the image is very bright, but at lower overall brightness levels, are no longer sensitive to it. I cannot speak from experience, as I am only occasionally able to detect the rainbow effect, and typically only when I'm tired.
The HD4000 is fairly reasonably priced for it's video performance plus all those lumens. By comparison, even Mitsubishi offers a brighter widescreen projector, the WD2000, which we hope to review, but it's list price is $5995 vs the $3995 for the HD4000, so you would have to expect the WD2000 to sell for around $1500 more. Other very bright projectors that are widescreen, include the Sanyo WF10, an LCD projector, with 4000 lumens and a selling price definitely over $6000, and even more expensive models from projectionDesign, DPI, and Christie.
Thanks in part to "Brilliant Color" processing, that is also found on Mitsubishi's HC3000 home theater projector, as well as others, including Optoma's HD72 HT projector, colors are rich and vivid, without looking unbalanced.
Rainbow Effect
Over the last year or so, I have mentioned several other DLP projectors as possible alternatives for the home. One sticking point (and this is true of almost all the DLP business projectors that have been sold to home users), is the speed of the color wheel. We are used to home theater projectors sporting 4x or 5x color wheels, to reduce the percentage of those sensitive to the rainbow effect to a couple percent of the buying public. Business projectors, though, typically have 2x color wheels, so a somewhat larger group will notice them. (Sorry, no good numbers as to the real world percentages, still, few return business projectors sold into the home market for this reason).
I am barely sensitive to rainbows, typically only when tired, and or by shaking my head and blinking my eyes quickly, on moving dark scenes with bright lines, to make them appear. With the HD4000, I definitely was able to pick up on those flashes of rainbows around bright objects, more easily than with home theater projectors. In fact, I was almost surprised, for a "business" projector, I thought it did pretty good, in this regard. No match, though, for dedicated HT projectors. If you are rainbow sensitive, you'll probably need to stick to a dedicated HT projector with a faster color wheel, or an LCD projector.
Well that concludes the longest Image Quality section I have ever written. By this time you probably sorely need a caffeine fix, before continuing to the general performance section.