The viewing angles of the PLS matrix are excellent when the monitor shows a bright colorful image. I could see no color distortion or contrast deterioration even at large viewing angles, both vertically and horizontally.
There was one interesting thing with black. To illustrate it, I made a few photos of the monitor from different angles in a dark room. The monitor works at full brightness and displays a black fill.
It is easy to see that the screen doesn’t get much brighter when viewed from a side, but the areas with backlight irregularities show some more light. Moreover, each such area has its own particular viewing angle at which it becomes the brightest. For example, the bright spot at the top of the screen moves rightwards in the last two photos.
For the comparison’s sake I will show you photos of an e-IPS matrix (Dell U2311H) under the same conditions.
The brightening of black has nothing to do with backlight irregularities (which have a rather typical X-shaped pattern on this monitor). As the viewing angle gets larger, there appear yellow-colored symmetrical spots in the far corners of the screen. These spots get larger along with the viewing angle.
So, it looks like PLS is indeed superior to e-IPS in terms of viewing angles, especially on black, and can compete with the more expensive samples of IPS matrixes. Besides, my sample of SyncMaster SA850 with a PLS matrix is prevented from showing its best in this parameter by its backlight irregularities. When viewed from a side, its screen gets brighter the most in those areas where the backlight is the most irregular.