Subjectively, the LS221H is set up neatly. It is good at reproducing halftones and does not have a bluish picture like many other modern monitors.
The monitor’s protective glass produces some flares but not as many as the now-popular glossy matrixes. This is not a serious inconvenience.
Typically for a TN matrix, the viewing angles are acceptable horizontally but too narrow vertically. The screen gets dark when viewed from below. That’s not a problem if you are sitting at the monitor, but TN-based monitors are not a good choice if you like watching movies while lying on a sofa and looking up at the screen. TN matrixes are still inferior to VA and S-IPS ones in terms of vertical viewing angles. Inexperienced users may even think that the characteristic darkening of TN matrixes when viewed from below is due to nonuniform backlight. Alas, monitors with matrixes other than TN have become too rare and expensive by now.
The LS221H has a very good response with no ghosting, but RTC-provoked artifacts (short white trails behind moving objects) are ubiquitous. They are not too strong but can be seen almost everywhere, even when you are moving a window with text. Unfortunately, the monitor does not allow to disable RTC technology and thus get rid of the artifacts.
There was a small glitch with the firmware. When turned on for the first time, the monitor reports it is in Standard mode and the screen brightness measurement yields 236 nits. However, if you then switch from Standard into some other mode and back into Standard, the screen brightness will be 193 nits only. The numeric values of Brightness and Contrast settings in the menu are the same in both cases. In other words, when you turn the monitor on for the first time (or if you reset its settings to the default values), its setup has nothing to do with the Standard mode or the numeric values in the menu. The monitor just has some arbitrary settings then. That’s a small but annoying problem, especially as such minor problems can often be observed with ASUS’s but not with other brands’ monitors.
The Splendid modes are disappointing. Save for Standard, each of them distorts colors greatly and I could not make them differ with brightness alone using the manual settings. Of course, it is good that you can manually adjust the brightness of each of these modes in ASUS monitors, but I’d like to have the opportunity to disable the color “enhancements and optimizations”, too.
Now let’s see how all this looks in numbers. I made my measurements in the Splendid Standard mode (except for the test of the Splendid modes proper).