Foto-z...the Samsung XL30..
Neil, you should have the screen replaced. That is usually due to poor triad calibration/sync of the LEDs in mfg .
I use Samsung XL30, and it would be hard for me to go to regular LCD as a main screen.
There is no flicker, no warm up, very little heat, less often calibrate, After 3 years you will not notice the calibration getting harder, screen getting dim.
Also, Neil...The XL30(As well as your HP) has the differnt hard button setting on the screen that you can toggle between profiles, and you can easily use sRGB.
The XL30 comes with a Eye1 screen specific calibration device and software(and a hood) to calibrate the LUT(I think it is 14bit?) in the screen not your vid card.
If anyone is in the market for a new screen, and can justify $2K or more (as one should get as good a screen possible if it is something you spend half your life in front of)....I would urge them to look at the 2 screen side by side if possible, you will notivce over time looking even at LCD there is a strain as it flickers. LED is solid. I use the LCD as my thumbnails and palletes window now. It is a super screen, but you do have to see them together. The colors are also dead accurate. I am a bit more confident with my proofing as it matchs the contract proofs very nicely. I love good technology, and even keep 3 24" crts in use, but to edit, I love he XL30.
I think qualtity control would be the only issue, and you really shouldn't accept a screen with uniformity issues. If you light up the screen with all white, and it is not dead neutral after a proper calibration, you shouldn't accept the copy in pro level monitors.
With all this positive stuff I said about the XL30, I am yet to get a 64bit version that is supposed to be out already. Also the screen will have a couple, one pixel thick line of garbage across the screen for a couple seconds and then disapear. This happens when I launch a program(not everytime), and it might be the frqcy of vid card? But once a week or so, and not enough of a bother to even take away from it. But Samsung should look into this as it is there, and should be something to clear out...if it is the screen and not the card.
The HP and the Samsung have many like features, and I wonder if it is a rebadge, as I don't think HP makes any panels or lcd screen parts?
As posted earlier, dont confuse white LED with RGB LED, The green benifits are there, but not the color accuracy or gamut.