Sharpness
I've been raving about the HC6800's image sharpness. This Mitsubishi just looks a tad sharper than competing projectors like the Epsons (regular and UB projectors), LG's CF181D and Sony's VPL-HW15, and most definitely the Panasonic PT-AE4000. Only the DLP's are as sharp, or sharper.
Black Level Performance and Shadow Detail
In a nutshell: Very good dark shadow detail, and black level performance that typifies a good, but not "ultra-high contrast" projector when it comes to black levels. If you've got the room, and the inclination for truy great blacks, the HC6800 isn't your projector, though the more expensive, similar, (though less bright) HC7000, might be instead.
The very bottom line
A great $2500 projector for the masses. Not quite as great a projector for the hard core enthusiasts who demand a step up in black level performance. That said, the projector is more sophisticated, than some directly competing projectors like the Epson 8100 and 9100. The Mitsubishi HC6800 should be an excellent choice for someone wanting a really nice, easy to operate, projector for their theater, or darkenable viewing room. It's a projector for the whole family. Let me put it this way: If I were to replace my old Epson 1080UB (which does have better blacks than the HC6800), with this Mitsubishi, my wife would likely only notice a few things - such as that it isbrighter when she's watching a movie, and maybe she'd notice that it's less bright for watching Glee, or American idol. That the Epson has better blacks or inferior dark shadow detail wouldn't even show up on her radar.
And while my wife may not be an enthusiast, you must consider that she does watch a lot - at least 10 hours a week using the Epson in "theater 2".
If you are a do-it-yourself type, shopping for each component based on price and performance, you aren't too likely to end up with the HC6800. If, however, your plan is to check out some local home theater companies, have them build out the room, and provide the equipment, and if you are not a fanatic for performance, but just would like a projector that the whole family likes and can figure out how to use, then the HC6800 fits the bill. That's particularly true if you are a movie (not home theater equipment) fanatic, who just wants to fire up your gear and enjoy.