I haven't compared the two side by side, but I find the LG black levels comparable to my calibrated CRT (definitely not as good as the CRT, of course). Be sure you have the black level setting correct, as this display seems to handle it differently than other brands/displays. For example, when using component I have to set the black level to high when using YCbCr when low should technically be the correct setting. HDMI black level has behaved as expected so far, though. Could you post the FCC ID on the back so I can be sure you have the same panel?
I used the Samsung EH5000 briefly last year, and I was impressed with its picture quality as well. But the overshoot and terrible handling of any motion outweighed the picture quality. I didn't mess with it too much, as once I saw the terrible inverse ghosting I returned it within days. But I did notice that it seemed to introduce a bit of black crush in the lower shades, which can sometimes give the illusion of more contrast/better black levels. But again, I didn't have it for long and it could have just been incorrect settings.
As for the screen finish, I find the LG to be almost TOO glossy (I can see the reflection of my computer monitor and lamp clearly). Not as reflective as my CRT, but still reflective. I detect no grain in the whites either.
I will be able to have some objective numbers regarding black level and more for everyone when I finish my calibration via spectrophotometer and HCFR by the end of next week.