I just got back from Fry's in San Marcos, CA. They had the 6168 on display.
To start with, I have never seen a TV look good at this place. I figure it is their source material/signal splicing.
I spent around 45 min with the TV with no interruption from the sales staff.
The 6168 was receiving a coax signal (ANT1) and a component signal from the same source (cable). Both were fed the same channel which was good for comparison reasons. It was tuned to TNT and appeared to be std def because the picture was not real detailed. It might have been HD...a crime if it was.
Initially, the picture was not that great (although better than everything else in the store: DLP, LCD, plasma). Fairly bright, a bit grainy, some motion artifacts. I immediately went to the menu. Thankfully, it was on the factory preset. I made some adjustments based on my DVE experience (lower contrast, sharpness and brightness). I didn't touch the color adjustments and tint. Tint can only be adjusted through the coax input and not component (I think 480p and above). I turned off the Samsung picture improvements (I forgot what Sammy calls them but there was two). Temperature wise, I lowered it to Warm 1 (slightly bluish and similar to Normal) and Warm 2 (slightly redder). Both seemed adequate and far better than the first two choices. I made the adjustment to both inputs since you can customize each.
These adjustments made a big difference. Jagged edges were gone as well as the motion artifacts. Most of the graininess disappeared was well, but was still present. I performed the "rainbow" test and, am happy to say, the 6168 passed. No rainbows at all. I performed the same test on several Mits. and older Sammy DLPs in the store, and did notice the split second rainbows when looking away and looking back to the TV quickly. Tried it several times with the 6168. No rainbows.
Brightness wise, it wasn't as bright as the JVS DILA, but that was after I turned down the factory adjustments. I assume the JVC was set to blow torch mode.
Picture wise, it looked better than any other LCD or DLP in the area, but I didn't walk away from it saying "wow". Nothing three dimensional or eye popping about it.
As mentioned, I would look to the signal source before making a final assessment. Based on history, this store could make a $40k three chip projector with the best external scaler look horrendous. The local Tweeters should have the 68 and/or 78 in stores this week, so I will take a look this weekend.
I have a 6168 on order with TVA (6/6 order date, no call yet). I'm not worried about today's results. Once I take it through a DVS session, and eventually a professional calibration, the new Sammy's will look great.