I had decided on getting a 500M and was about to pull the trigger. Then yesterday my wife and I were in a BB. We stood at approximate viewing distance (say 10-12 feet or so) with a 50" set right over a 60" display, and I asked her which she thought would work best in our relatively small living room. To my great surprise, she said the 60".
So . . . the 500M is regarded as a better display, though it's not clear how significant the improvements are in a real-world situation, and would be about $800 less expensive; the cost difference is not a deal-breaker but hey, $800 is $800. The 600M has, obviously, a lot of extra real estate in its favor.
In either case, the display will be professionally calibrated and will have the ISF patch.
Thoughts? Are the improvements in the 500M enough to tip the scale, or would I likely not really notice the difference?