Thanks Vic12345 for the post.
I think the ABL is what I was looking for because I am disturbed by the symptoms that are described here -
http://www.avsforum.com/t/1347781/auto-brightness-limiters-abl-in-plasma-sets
I've seen ABL mentioned a lot, I didn't know it was the same thing I am worried about myself.

I am used to the LCD panels, this is the first plasma I am looking at at my home.
I can't get used to the fact that the contrast is wrong going from dark scenes to bright ones/screenful of white. The contrast in brightness is lifelike and okay in one picture across the screen (not sure it retains the contrast when little dark figures on white screen because the white is too dark and dark parts can't go any darker for the minimum black level is the limit) but it isn't lifelike in the sequence of frames if the scenes that go from dark to very bright or vice versa. Getting that right would make the video a lot more lifelike for me. The picture can be excellent, but not the video (wrong contrast between different scenes).
It was interesting to read how you would calibrate your brightness and white balance.
I think I could use some of that if I were to calibrate again soon with my bare eyes and no test patterns. I was using AVSHD709 basic patterns in MP4 form for my initial settings. I've fiddled with the WB and the settings already and I think I can't get the colors much better. Colors aren't right in every part of the screen. Some parts tend to be reddish when bright screen, some greenish, but it wont be noticed by the average viewer. Not sure what is going on there but I am not returning the TV of this price for that.
Overall I think the colors of my Philips PC monitor are much more accurate across the screen.
What I like about this Samsung TV is its upscaling quality of SD content. I am watching a lot of terrestrially broadcasted SD stuff in 576i resolution and it looks like it is at least 720p (when looking from 3m distance, it is watchable at 2.5m too, got the 43'' model) compared to other TV brands. I've never seen better SD picture in any TV in any store or anyone's home.
For the SD to be perfectly good I am using the sharpening set to no more than 10. (Think it depends on the SD content quality a lot, I am getting good quality SD MPEG-4 content broadcasted here.) Can't imagine setting it at 50 or at least more than 15, 20 looks already bad for me. (It would lose details in the picture as would not turning off all the noise reduction stuff. I can't stand losing information in picture.) For HD content using sharpening set at 0.
Also like the viewing angle.
The guy in the TV shop seemed pretty confident that this ABL thing can be turned off in Samsung TV's with some codes, so I am searching the net for more information or going back to the guy some day to ask if he knows these codes.
Not sure everyone would use these codes. Power usage can go up a lot, I guess. Maybe at least 1.5x. But that is not the concern for me.