I hate new 120Hz and 240Hz modes on televisions and I know exactly why.
Many people complain of the "camcorder look" produced by the 120Hz modes on new, modern TV's. Basically, the Hz rating of a television is the number of times per second that the screen changes. So, theoretically, the TV is capable of producing 120 frames per second. Sadly, TV broadcasts are 30fps, and movies are 24fps. Even most video games don't go higher than 60fps.
Now theoretically, 120Hz is a holy grail for home film reproduction? Punch it into your calculator, it's the lowest common denominator for 30 and 24, and that's big. That means that every frame of a film's 24fps multiplies into an equal number of screen frames. Specifically, five frames. Currently, televisions refreshing at 60Hz have to perform an action known as the 2:3 pulldown. That's the only way to distribute 24fps evenly across 60 frames.
But with 120Hz, oh baby, each frame from the film's 24fps is displayed on screen for an equal 5 screen frames. Or with television, each of the television signal's 30fps is displayed 4 times. Or each of a video games 60fps is displayed twice. This means that video from any source is reproduced smoothly.
Unfortunately, television manufacturers are trying to find ways to advertise their sets beyond what should be done. This piece of marketing shit is called motion interpolation. We'll use film for example. Instead of displaying each frame from the film five times, resulting in 24 images seen by the viewer every second, the television will create new frames from the information contained in the 24 original frames to fill the full 120 that the TV is capable if displaying. Theoretically, this should result in smoother motion, without any of the jittery display commonly associated with film footage on TV.
Too bad it doesn't work. Everything in modern video technology is based around the old limitations. DVD's were mastered and the films were filmed with 24fps in mind. Television is made with 30fps in mind. Trying to interpolate your way past it cannot remove some of the details. Film looks realistic because it is the closest thing to human sight we can achieve with images captured. If something is moving quickly, 24fps gives us motion blur. Trying to interpolate frames in between that results in abnormal motion, because the human eye does not see in 120 perfectly distinct moments every second.
Things blur and flex as they whiz past. They do not go past us quickly while remaining perfectly clear the whole time. 120Hz does not capture how we see the world. 24fps does. Just think about taking a photo. If you set the shutter speed to 1/24 sec, and have someone move, the motion is captured in the frame. If you set the shutter speed to 1/120, you have much more of a "freeze-frame" look, with more detail, but less motion. In early cinema, they discovered that the amount of motion and detail captured in 24fps best approximated human vision. When they first started making film, they could have gone faster. They could have done 30fps, or 45, or 52, or any other random number, but they didn't. They did 24 because it looks right. 120 looks terribly, horribly wrong.
This is especially problematic for animation, which tries to approximate that sense of motion with each frame. For example, unlike something that was filmed, animation might use weird, exaggerated frames to make the in-film motion appear smoother or more realistic. Interpolating frames in between frames that were drawn specifically with 24fps in mind results in a unsettling, too-smooth look that seems to run too fast, because most of the interpolated frames are trying to "catch up" to the actual frames from the movie.
This is not a matter of taste, where I'm merely used to 24 and will get used to 120. 120Hz interpolation is breaking what was made. It cannot possibly alter everything about film creation to make it look good. If a film was made with 120fps, and everything was calibrated to make that 120 look good, that would work just fine. But we don't have that. We have 24fps, or 30fps, which looks like shit when bumped up to an artificial 120fps.
My advice to you, if you buy a new TV, find out how and TURN THAT SHIT OFF. Just say no... to interpolation. Or, if you prefer, friends don't let friends interpolate. Or, give a hoot, don't interpolate. Only you can prevent interpolation. Or one that actually rhymes: unless you hate, don't interpolate.