How do you like it?
Is the RGBled worth the extra?
I am just about to get one, and see very few review/reports by working photog's.
I love this computer! The Precision M6400 is the fastest machine (desktop or laptop) I have ever used. The Quad Core Extreme 2.53Ghz CPU is very quick, the Nvidia Quadro FX 3700M with 1GB is crazy fast for video rendering, and having up to 16GB DDR3 RAM makes multitasking easy. Quad core is really nice for Lightroom exporting, Premier Pro video rendering, Capture One conversions, and anything else that is properly multithreaded. My other (travel) laptop is a Core 2 Duo 2.53Ghz and I can really feel the speed advantage of the quad vs. the dual at the same clock speed.
If you can spring for it, I hightly recommend the dual RAID 0 SSD route. I'm getting more than 300MB/sec reads and writes with my two Samsung 256GB drives. This combined with the CPU and GPU horsepower make this the most responsive and highest performing system I've had the pleasure of using.... and I can take it with me.
And, to answer your question, the RGB LED screen is the closest I've seen to matching the color gamut and smoothness of my Eizo. Not quite as good, but much, much better than any other laptop screen. You do have to put the brightness at about 20% to get to 120cd/m2, but it still looks great. I opted for the anti-glare version, not the Edge-2-Edge glass screen, as I believe it to be better for photo work.
I'm running Windows 7 64-bit which works completely flawlessly. I have the CS4 Master Collection, LR 2.4, and C1 4.8 and they all work perfectly in 64-bit.
One other nice thing is the amount of port options. I have Firewire, 4x USB, eSATA, Display Port, PCMCIA, and ExpressCard 54. In my ExpressCard slot, I'm using a Delkin CF reader which uses the PCI-Express bus for about 50MB/sec throughput. So, along with the built-in SD reader, I also have an internal CF reader as well. Very convenient.
If you can live with the 8.5 lb weight and limited battery life (only 2.5 hrs), you will be rewarded with a blazingly fast workstation that can go on location with you.
David