The Samsung XL20 has a high bit internal lut so you want to get their software or Coloreyes (on the mac) so you can take advantage of the additional precision provided.
I tried their software and got errors - but I think that's 'cause I was (an idiot) trying (ie failing) to write digital data to the monitor LUT over the analog input. I need a docking station for my W500 so I can use the real DVI. In the interim, I'm stuck with what I'm doing now.
Here's where I've ended up ... the monitor in native state is quite bright and cold - temp measures around 9500K. I used the Spyder3Pro to physically calibrate the monitor via OSD control to very close to 6500K and 120 luminance by a combination of a Warm 3 and a few tweaks to the RGB sliders. I then profiled it with the Colorvision software.
I think it is a good profile ... but I'd prefer to be doing it via the monitor LUT since it has that capability.
I think once I get the dock, I'll get the ColorEyesPro software and do it "right".
I've learned A LOT in the last two weeks ... thanks, all!