I'd suggest you post in the Dell 9300/XPS2 forum (though many of the old-timers there will groan at another "sparkle" post).
I have a 9300 with a Samsung WUXGA screen, and I got this one via swap from my last replacement Samsung screen, and that one was a swap from the original LG WUXGA screen that came with the machine.
So indeed, the two vendors supplying WUXGA Truelife screens for Dell in the 9300/XPS2 are LG and Samsung. Its a crapshoot which you'll get when you order one of these laptops. By the way, Dell's "TrueLife" is their code name for an lcd panel with a glossy coating, just like Sony calls their version "XBrite"...
The "sparkle" everyone talks about, well, no one can agree what causes it. My take is: the pixel pitch of the 1920x1200 screen is 0.191 mm, and this fine pitch mixed in with the way LCDs wornk causes a very fine pattern of polarized light that looks sort of like a fine grain or texture to light/white areas of the screen. The better/best glossy WUXGA screens out there (on Sony and Fujitsu laptops IMO) use optical coatings to reduce/eliminate this, I think. The Dell screens don't do as good a job.
Now, specifics: the Samsung IS less grainy than the LG, though the LG has slightly better colors out of the box (the Samsung can be color-corrected to the better colors of the LG). The Samsung doesn't have quite as good black levels as the LG and usually has more light leakage, but it has the most accurate gray scale I have ever seen on an LCD...
I like mine and I'm keeping it, for what it's worth.
Say you order a 9300 and you get the LG screen. You live with it for a week to see if you like it, but decide you want the Samsung, so what do you do? Well, I call it "LCD Roulette." You basically tell Dell the screen is bad because of light leakage or some such, they swap the screen out with a replacement (several options on how this is done), and maybe you get a Samsung, and one that you like. If you don't, repeat the previous step. And so on and so forth.