How much better than Sharp 12kMk2?
For my 12kMk2 I bought a new lamp - only $189. The original lamp is 230 watts and the new lamp seems about 160 watts. The filament seems suitable for LCD projectors due to their greater efficiency. Previously I used only econo mode and in high contrast iris for best picture, and I switched to high brightness iris from 1000 hours.
Probably better to call Sharp and purchase replacement lamp from Sharp. This new lamp looks too dim. My instruments don't measure wattage, and I have no way to prove wattage is not correct.
Amazon had great price for BenQ w6000 with 30-day trial. Sharp claimed 1000 lumens for 12kMk2, and BenQ claimed 2500 lumensfor w6000 with 280 watt lamp. Gave w6000 a try.
Brightness, w6000: in econo mode, far brighter, and well suited for progessive lamp dimming.
Constrast, look about same as 12kMk2. With iris opened for high brightness, Greg Rogers measured 2000:1 for 12kMk2. He measured 3000:1 mid contrast, and 4000:1 in high contrast. On this site, someone measured 1000:1 for w6000, but Digital Iris might account for darker appearance than 1000:1 when viewing black bars. I guess BenQ switched from DarkChip2 to DarkChip3. BenQ never specified chip, and this allowed them to make a switch. Sharp 12kMk2 uses 0.95 inch DarkChip3.
Black level, about the same as Sharp.
Resolution, w6000 seems sharper than 12kMk2. Sharp used expensive Minolta lens and BenQ used a cheap lens, but this cheap lens projects an obviously sharper image. Probably smaller 0.65 inch chip allowed use of smaller, low-priced lens.
Lamp hours, 2000 hours in high brightness mode; 3000 hours in econo mode.
Anamorphic 2.35 projection with adapter, electronic vertical scaling built-in for DVD as well as high-res HD-DVD and Blu-ray. One-button press from remote. Sharp 12kMk2 has vertical scaling for DVD only, and for high-res you need a separate video processor.
Using HP screen, w6000 might be unsuitable due to extreme brightness.
Recommendation: for black level enthusiasts like you, JVC RS45 seems an excellent choice.