Very happy with my W520

Question

My W520 is working flawlessly in a docking station. I have to use Throttlestop just in case to avoid any possible throttling, but apart from that precaution, it works great. i7-2820 + Quadro 2000M + 2 Vertex 3 240GB in Raid 0 + 16 GBytes of RAM. Awesome performance in a high quality package.
I give it 9 points. After they fix the small details in the BIOS with the ocassional throttling (which can now be avoided with Throttlestop), I will give it 10 points.
Great piece of hardware.

Answer 1

Interesting tests, mgoldshteyn. As a reference point, on my W700 w/400NIT 1920 x 1200 17" display w/dual-fluorescent backlights (and calibrated with built-in calibrator), I see all the black/white squares (the blackest black square being a challenge, but barely visible).
Of the colored screens, the only one where I see any variations at normal viewing distance is on the purple screen, and I do see the difference in "lagom" across the screen, which is probably typical for TN displays. This is all with the browser set to full-screen, to avoid having the browser interface take up any of the display area. And this is all with the brightness cranked up to max. I didn't test at any other brightness.
Just for kicks, I also ran the tests on my HTC EVO 3D Android phone (at full brightness), which has a 4.3" 960 x 540 Super-AMOLED touchscreen display. The EVO 3D screen allows you to see all of the black/white squares (the blackest black square, and whitest white square being a challenge, but still visible). And the colors are all absolutely uniform across the display. Brightness was just as good as the W700 display, but colors weren't quite as saturated, although hues appeared close to those on the W700 screen. I couldn't do the "lagom" test on the phone, because I didn't have an easy way to display that screen at native display resolution (you pinch and expand to rescale the web page on the display, but nothing indicates whether images on the page are at native resolution). The EVO 3D screen can also simultaneously display two images, using a built-in parallax barrier that channels a separate image to each eye, to show 3D images/videos without requiring special glasses (plus the phone has a built-in 3D still/video camera).
As the contrast ratio of production laptop displays go higher, which is the trend, you're going to see less and less of the black squares. People often like high contrast and brightness on TV displays, but that's not always so great on computer displays, particularly for people like myself who do image processing work. That's because you lose shadow detail, which is often important in image processing.
The issues you dislike regarding the W520's brightness settings probably have to do with the fact that, with LED-backlit displays, overall screen brightness is controlled by changing the duty cycle (instead of the intensity) of the backlight. That places a constraint on available brightness levels, because certain duty cycles, combined with the screen's refresh rate, will cause an apparent flicker in the display (which occurs mainly at lower brightness levels). And if that flicker were to occur, you would certainly complain about it, when you weren't busy vomiting or taking aspirin for your resulting headache. But the W520's display is not incredibly bright to start out with (at least according to notebookcheck.com), so most people would probably use one of the brightest settings anyway. Plus it loses additional brightness if you color-calibrate it, since the brightness of one or more color channels will then be reduced (plus people complain of oversaturation of reds with the built-in  calibrator on the displays of the W510/W520/W701, and  more advanced external calibrators have been recommended in such situations).
If you want a laptop with a better display, the best you're going to do at this time is to buy one with an IPS display:
http://www.techinferno.com/2011/03/01/hp-elitebook-8740w-review/
BTW, if you like, here's another test you can run on your W520's display, just for fun.