I got my pn58a550 on Friday.
First impressions are great. Good 1080i TV source via component looks perfect (with cnet HDMI settings). Excellent black levels and no reflectons on the screen, although my room is not very brightly lit. The bezel reflects stuff, but not the screen.
I am comparing it by memory with the 60 inch Pio pro plasma, setup and excellently calibrated in the dark Magnolia room - I can pick up no difference whatsoever besides size, but that is by memory, not side by side. Maybe side by side there is better black level on the Pio pro, but it has a $7K sticker at Magnolia, not final price of course. I am completely satisfied with the black level of the Samsung.
The can be adjusted to anyone's personal taste - from very bright and striking to eye-friendly and natural, with proper skin tones. I ended up using the cnet settings as I have not had time to eval the settings in greater detail and calibrate the TV.
There is a moderate dim light below the bezel and it can completely be switched off.
There are buttons on the right side that are totally unnoticeable. in fact i accidentally turned off the TV a few times - did not see the buttons and was trying to rotate the TV.
Sound is good for a TV speaker. I am connecting to external speakers so I did not play with sound options at all. Just found that there is a way to switch off sound completely from the menu - exactly what I will need.
SD quality varies greatly - with a good clean and clear digital cable channel it is perfect, with very low quality and noisy analog signal the TV is not perfect, and it is worsened by its size, every imperfection is magnified greatly. There are noise reduction options in the menu, they help a lot, but of course are not 100% efficient.
At the brightest default setting (Dynamic) the TV heats up to a good level. At the Movie setting and the CNET setting, it is warm-hot, closer to warm - very acceptable temp, I have seen hotter LCDs.
The TV is very heavy. The screen is actually slightly tilted back on its base, like 1-2 degrees. I guess the designers realized that when the TV is placed on a stand, the top stand shelf will "sag" a little, back to front, and the screen will become totally perpendicular to the floor
You really need a good sturdy stand for this one, and I would never risk wall mounting it with a tilting/swiveling mount.
I have not connected a high def DVD source yet, and have not tried the 24 fps movie mode.
I have tried briefly for 10 mins, in the Dynamic mode, watching ESPN with static logos, then switching back to grey bar-ed SD channels and to regular HD programming - I did not see any IR. I will later try completely plain screen, not sure for now about IR. But in real life conditions (just watching TV) i do not see any problems.
I tried running this a a giant picture frame with an SD card with a bunch of 3mb jpeg files. The interface and menus for USB playback are excellent. The speed of rendering images is bottlenecked by the SD card speed.
I am happy I did not go with an LCD, was considering LCD only to be more energy efficient, but finally gave up and went for the pic quality.
The shiny bezel serves a double purpose - it also indicated the dust level in the house
I did not know I had so much dust in the air, after one day lots of it clung to the bezel. I can't see it on the screen though - ether because the screen is so good swallowing light, or because the bezel just attracts the dust due to its material electrostatic properties.
After getting used to a 58 incher, I cant watch smaller TVs anymore