Your point? You are only echoing what I already said.
Which is to say that unless the source material was recorded at the same native refresh and resolution as the display there will always be processing involved either to fill in for refresh rate or to upscale resolution. Which doesn't really matter since most people can't tolerate having bars on the screen and opt for the least distorted display of the source that fills the screen.
My point? Accuracy.
I am not echoing you - I am actually saying something completely different than you are.
"Processing" is a somewhat ambiguous term. When I think of processing I think of MotionFlow - which literally creates frames that do not exist. This process creates the "artifacts and smearing" that you are speaking of.
120Hz / 240Hz sets are nice because it allows you to view all common fps 24, 30, and 60 at proportional frame-rates because they all divide evenly into 120. There is no processing of the image - depending on the native fps each frame is repeated either 5, 4, or 2 / 10, 8, or 4 times. There is no reason that playing any of those native fps material on a 120Hz set would cause ANY "artifacts or smearing."
A Primer:
If you pop a 24fps Blu-ray disk into your Blu-ray player and you have a 1080p 120Hz display it will play the movie by simply repeating each of the 24 frames 5 times. There is no "processing" of the image - it is at its native resolution and proportionally native frame rate.
If you are watching TV 1080i 30fps the image is deinterlaced and each frame is repeated 4 times.
If you are watching TV 720p 60 fps the image is upscaled to 1080p and each frame is repeated 2 times
If you are watching TV 480i 30 fps the image is upscaled to 1080p, deinterlaced, and each frame is repeated 4 times.
The repeating of the frame is NOT creating ANY artifacts, PERIOD.
UNLESS the display does allow scanning at the recorded refresh rate natively. From what I have read, several do not, thus they use some form of interpolation. For these, the user controls only allow one to select what manner of interpolation gets used.
Interpolation is a process where the standard repetition of the same frames is modified so that it is not repeating each of the frames a set number of times but rather is creating frames. The display will still be showing a 1080p image at 120Hz.
Standard:
111112222233333444445555566666777778888899999......23232323232424242424 = 120 frames
Each frame is repeated 5 times.
Inerpolated (MotionFlow)
1 1.1 1.2 1.4 1.4 2 2.1 2.2 2.3 2.4.......... 23 23.1 23.2 23.3 23.4 24 24.1 24.2 24.3 24.4 = 120 frames
Each frame is shown only 1 time. 1 source frame followed by 4 created frames. All of the ._ are created frames. This is where a ton of artifacts, and blurring come from. Turn this feature off.