This filter isn't for everyone, and you can say it's gaudy too, but I won't knock any points off that because if this is the effect you are looking for, it's actually really fun and does remind me of the 80's/90's.

The filter is made very well, and the glass is CHUNKY and thick. I got the 82mm version and to be honest I found using from a 16mm lens up to a 200mm lens the results and composition really vary and I didn't exactly find a sweet spot because it also varies with the size of your subject. Taking pictures of smaller flowers was better at a certain focal length, were as portraits of people and things like cats worked better at others. What I mean by better is have it where the 5 other diffracted floating points aren't really creating a major distraction to the center point.

The effect is interesting. Almost like a bug eye kaleidoscope effect. I uploaded a video of my cat for you guys to see. It would of been neat if there was a lip on the filter to spin it easier during video, but you can see the intended results of the lens easily.

The filter doesn't really affect the clarity of your lens either. Overall if judged just on on how it's made, the effect it does, and how well it works, I can't really find any fault in the filter at all.