I will try to make a screen of the glitter, but I'm not sure it'll work, it's very very fast. (less than a second I think)
And yes, it only appears in softmode, never in OpenGL mode.
Just so you know, the first version I tried was the 0.11, and at this time, they were not openGL options available, only the softmode. I was not having any glittering at this time, but I couldn't apply the screen filtering. In fact, checked or unchecked, it was making no differences at all. Now, I can have a very smooth filtering in softmode, perfect for 2D games, but with a weird glittering.
When I was saying that OpenGL makes the games look worse, I was only speaking about 2D games. For the 3D games, it's way better. I haven't tried any full 3D games such as Spyro or Crash Bandicoot, but I'm sure it looks really nice.
But the only games I tried are FF9 (which contains a lot of 2D parts), Legend of Mana (which is full 2D) and Tales of Phantasia (full 2D too, except for the world map). So for a game like Legend of mana, the OpenGL plugin is useless, as I don't get any filtering: the result is a very pixelated game. The softmode with the screen filtering enabled is a much better option.
Maybe on 4" phone screen it could work quite good in OpenGL too, but on a 10" tablet screen, you really notice a big difference.
I used to play a lot with Epsx and the Pete's OpenGl graphics some years ago. I remember that you could really enhance the graphics, even the 2D parts, and get a perfectly smooth game, even with an average computer. They were tons of options, it was sometimes hard to understand what they would do, but it was a nice job!