Pros: Advanced anti-glare
Excellent picture quality for cartoons and animation
Above average reputation for customer service
Cons: Poor color depth
Constant color shifting
Unnatural boombox audio
Humble remote with stuck buttons
Soon after buying the 2008 Samsung 42" 720P PN42A450 plasma HDTV I moved it to the children's room and bought the directly competing Panasonic TH-42PX80U to replace it. My hope was that the Panasonic would program in and save more cable channels than the Samsung. Sadly, neither one is able to program in and save as many cable TV channels as my 2006 Olevia LCD HDTV. Neither one can permanently program in and lock down common part-time cable channels such as foreign language channels. With the 2008 plasmas, channels programmed in as FAVORITES are erased each time the channel goes off the air when the TV is in use.
The above issue may not be a concern to most people, so I will move on to other matters.
Before turning on the power, comparing the Panasonic TH-42PX80U side-by-side to the Samsung PN42A450 many differences are noticed. It is obvious that the Panasonic's screen is darker than that of the Samsung. The Samsung almost has a brick red hue. Neither is pure black, but the Panasonic is slightly darker. The Samsung's screen is more glossy and reflective, while the Panasonic's screen is much more LCD matte-like.
Also before the power is turned on, it is obvious that the Samsung has a better remote. The Samsung's remote is bigger, with more buttons, and sad to say, new out of the box the Panasonic's remote buttons sometimes stick when you press them. Most frustrating is the up channel button sticks when surfing channels so the channels rapidly change until you fix the button back in place.
All of the TVs I have ever owned have had a right handed remote (channel-up and channel-down on the right hand side). Holding a right-handed remote in your right hand, your thumb easily rests on the channel-up/down area. The Samsung, all of the Sony CRTs, Olevia, cable box remotes -- all with right-handed channel buttons. The Panasonic TH-42PX80U's remote has the channel-up/down buttons on the left side of the remote. It is like trying to drive a car with the gas pedal on the left side of the floorboard... It feels unnatural.
About styling, the Panasonic has a stationary stand (that requires two people to safely attach) while the Samsung comes with an attached modern looking swivel stand. The Panasonic has a thinner bezel or frame so its total width is slightly less than the Samsung's. Side view, both seem equally skinny and both seem to have metal (not plastic) backs. To my eyes, both TVs have good styling. Different, but equal.
Turning the two plasma TVs on, and after turning down brightness, contrast and doing other fine adjustments, the Panasonic handles scenes with large areas of solid bright white better. The Samsung has a more noticeable flicker when there are large areas of solid bright white. However, the Panasonic seems to have much less color depth than the Samsung. Human faces, even in HD, look a bit cartoonish or like claymation. Faces look somewhat like talking pink balloons compared to the Samsung. Watching DAVID LETTERMAN in HD interviewing a pretty actress, it seems I can look more deeply into the actresses' eyes with the Samsung. Side-by-side, the Samsung makes real people look more natural. I have adjusted the Panasonic's picture controls up, down and sideways, but it seems that the Panasonic has fewer facial hue colors to offer than the Samsung. The Panasonic has 15,000:1 native contrast which is less than the native contrast of the Samsung, so perhaps contrast also has something to do with the less than natural look of human faces.
Equally distracting with the Panasonic is that its color slightly shifts on its own. In a steady shot, reds go more purple and then go back to red. Even more distracting is in a changing scene (say the view is cut back and forth as two people have a conversation), each time the view is cut there is a one or two second period where the color tone shifts or adjusts. It does this regardless if the Panasonic's Color Management Mode is turned on or turned off.
The audio from the Samsung is more natural for movies and TV shows. The Panasonic sounds great when there is music, but regular voices sound unnatural (like a radio announcer from a booming stereo system in between the music) no matter how I make adjustments in the audio menu.
As far as functionality, both have the same aspect ratio functions except that the Samsung has Zoom 1 and Zoom 2, while the Panasonic has only Zoom 1. However, I don't see much use for Zoom 2. I probably will never use it. One true weakness of the Panasonic is that to adjust the zoom (to keep heads from being cut off), one must navigate deep into the menu. But with the Samsung, adjusting is possible the moment the ZOOM button on the remote is hit.
Another frustration regarding functionality is that if I enter Channel 150.3 on the remote but it has gone off the air, and so I then hit the up-channel or down-channel button, instead of surfing to the nearby simular channels such as 150.1 or 151.1, the Panasonic wormholes all the way back to Channel 1 (or the lowest active channel) if the down-channel button is hit, or all the way to Channel 999 (or the highest active channel) if the up-channel button is pressed. This is annoying.
With its weaker picture quality and bothersome remote, after weeks of fiddling with the picture adjustments I gave up and put the Panasonic in the kid's room and moved the Samsung back into my TV room.