Answers and more below...
2D IMAGE QUALITY
We have to say, of all the projectors that have passed through our labs, the W1070 is one we'll remember. Yes, the price is low and it has lots of features, but most importantly, the image quality is practically irreproachable.
At 3 metres from the wall, you can set the image to be anywhere from 2.03 m to 2.64 m horizontally, which is better than most projectors.
The loudest, flashiest colours come out a tad too loud and flashy. (Note: the camera we used to take this photo slightly amplifies the image's flaws).
Surprisingly, we prefer Standard mode over Cinema mode on the W1070. The colours are more accurate in Standard mode (average Delta E = 3.3), especially shades of grey, pastels and flesh tones. Bright, flashy colours are the only ones that are exaggerated in any way, but it's hardly noticeable (Iron Man's reticles in the shot above stand out just a bit too much from the rest).
With 1% white test card in Standard mode: contrast = 1330:1
The contrast is just above average. We measured it between 340:1 and 1330:1, depending how much white is in the picture. The black level is excellent for a video projector: between 0.07 cd/m² and 0.26 cd/m². The only real problem is the low white level. Both on our 35% white test card and our 1% white test card, the brightness maxes out at 90 cd/m² (measured against a wall). So if you want to watch a movie in optimum conditions, you absolutely must be in a pitch black room.
Even more surprising, there's very little rainbow effect. We had our most rainbow-effect-prone colleagues try out the W1070 and they all agreed that it's there, but far less so than on other projectors.
3D IMAGE QUALITY
Like all household video projectors, the W1070's 3D feature uses active technology. The advantage with active 3D is that it effectively side-steps the exorbitant cost that comes with a polarised screen, and makes the projector easier to install.
Given the low price, it's no shocker that the W1070 doesn't come with 3D glasses. Unfortunately, they cost £80 from BenQ's online store, so for a family of four, they'll cost you £320—about 40% of the cost of the projector itself!
You can see no R overlapping the L, and no L overlapping the R. Perfect 3D!
The 3D rendering on the BenQ W1070 is astounding! Thanks to the DLP technology, there's absolutely no doubled, overlapping image (crosstalk) like you often see with LCD projectors. This is even better than plasma TVs, which show a certain amount of crosstalk in pictures with high contrast (white over black). Here it's flawless!
3D rendering: when you put the glasses on, the reddish overtones disappear
It's weird: in 3D mode, when you aren't wearing the glasses you can see heavy red overtones in the black. But when you put them on everything goes back to normal. Our guess is that BenQ did this to compensate for lower brightness and colour changes caused by the lenses...
We did notice one flaw in the 3D: with certain movies (Monsters vs. Aliens is one) our glasses lost sync with the image a couple of times. Perhaps it's because we were using a test model; it's hard to say.
HARDWARE & HANDLING
The BenQ W1070 is made of nice materials with good finishing. The image setting controls are on the top of the projector. It has a lens shift, which is rare for a DLP projector, but you don't have much room for manoeuvre—the image only moves 5 centimetres up and down.
On the back is loads of connectivity: HDMI (x2), VGA, Composite, S-Video and YUV. BenQ added a line input and an audio out for sending the sound to an external speaker system, which is good news because the built-in 10 W speaker is anything but impressive.
One of the few downsides to this projector is that navigating through the menu can be a pain—and it's all due to the remote control. It's small, the buttons are microscopic and it isn't backlit.
NOISE & ENERGY CONSUMPTION
But the biggest drawback to the W1070 is the fan noise. We measured it at nearly 40 dB from one metre away, which is loud enough to notice during quiet scenes in a movie. The best solution is simply to position the projector as far away from your couch as possible.
The BenQ W1070 consumes a lot of power, but for a video projector it's average. Our wattmeter picked up 206 W while running and 0.3 W on standby.