If you consider those pesky warranties, you need to spend $169 for the extended warranty for the Dell, to match the three year loaner program of the Panasonic projectors. That cuts the price difference in half. By comparison, with the networking version, you are starting with a 50% higher price compared to the Dell, so still a significant price differnce even if buying a Dell warranty.
OK, to the LB60NTU, I've already raved about it's wireless networking capabilities. If you need wireless networking, theirs is fast, easy, flexible, carries audio as well as video (rare), and can do a fairly large sized video, at frame rates that are smooth.
Combine that with rich, saturationed colors across the whole spectrum. Add the sharpest image of the six projectors, and it keeps getting better. Inputs are as good as any, with two computer inputs, one which can be a monitor out. I would have liked to see a digital interface, but most can easily live with the Panasonic's capabilities, and having a full set of three audio inputs, plus variable audio out, make it by far the most flexible in terms of audio.
Video performance is very good for business and education videos, but contrast levels and black levels are only average for LCD projectors and not really suitable for home theater type viewing.
Don't forget Panasonic's Daylight View feature, a nice touch that automatically senses the ambient light in the room and adjusts the image to best deal with it. It's not a "killer app" that makes a world of difference, but it does improve performance slightly, and, easily (the whole point of Daylight View).
The Panasonic's are pretty light, in fact, they are second only to the Optoma TX700 in this review, at 5.7 pounds (NTU) and 5.5 pounds (U). Their footprint is not much larger than the other projectors, and the unit is lower profile, for simliar bulk (except for the TX700).
I want to point out again, that the Panasonic's have a great 3 year warranty, with a loaner program for all three years.
If you desire wireless networking, lots of power, plenty of flexibility, and a great image, the LB60NTU is hard to beat, and certainly earns it's Hot Product Award.
The LB60U, gives you a high power LCD projector for a lower cost, and is equally worthy of consideration, especially if you need more flexibility than the Dell 2400MP. For those who like the overall aspects of the LB60 projectors, but don't have the budget, I should note that Panasonic's LB50 series projectors are almost identical, but smaller, lighter, and not as bright.
The HD4000 offers the best color handling of the four DLP projectors but can't quite match the excellent bright reds and yellows of the two LCD projectors. As a DLP projector, though, it has excellent contrast and very good black levels, that are so coveted by home theater types and those needing excellent video overall.
When handling component video, the HD4000 is particularly impressive. The only real downside is the 2X color wheel, so some may detect a bit of the rainbow effect. All of the DLP projectors have the 2X wheels so it has no advantage or disadvantage compared to them.
The HD4000 is certainly the best of the six projectors if you want to double it for home theater, or use it exclusively for home theater as a bright projector. That means you are mostly trading off the issues of the 2X color wheel, against the HD4000 having two to three times the lumens of typical home theater projectors, so better able to handle some ambient light (see the HD4000 review for screen shots comparing it to a typical home theater projector in a room with modest light coming in from outside. It does have one video flaw, that I should note, In large bright areas I noticed a bit of posterization. I have addressed this issue with Mitsubishi engineers to see if this is typical, or if there may be an issue with my review projector.
The HD4000 lacks audio capabilities, and this may be an issue for some. I believe Mitsubishi considers this a serious projector for video. With that in mind, the usual one watt speakers that other projectors sport, would be inadequate for serious video with audio, and users would demand better quality external speakers than a small portable projector can offer.
A good backlit remote, a great warranty, and a very good selection of inputs, make the HD4000, flexible, easy to use, and should provide you with good peace of mind.
One more word about pricing. While I was reviewing the HD4000 I was advised of a price drop, and as mentioned above, the MAP pricing is now $2495 (it was $2995 when I started the review). From a price performance standpoint this really helps the HD4000, which did seem expensive even for a widescreen. There is at least one other widescreen, the Optoma EP1690 which was originally to be reviewed, which sells for less. We will be reviewing that projector shortly, but if "traditions" hold, the Optoma will be less expensive, but won't quite match the Mitsubishi in contrast, and possibly color handling. We'll have to wait and see. I base that thought on my reviews of their equivilent home theater projectors - the Optoma HD72 vs Mitsubishi HC3000. (Two Optomas are similar in many ways, as are the two Mitsubishis.
But, I digress. In summary, the Mitsubishi produces very good data images, excellent video performance, and a great warranty. The HD4000 is priced reasonably for a widescreen projector, and should satisfy the needs of most that need a widescreen projector for business or education. it will also serve very well as a home theater projector for those needing more lumens than dedicated home theater projectors, with the caveat that the rainbow effect may limit a number of buyers from choosing this or most other widescreen DLP projectors.