I have til now, had little interest in red dot sights. And with the earlier PC9/4, the ghost ring sights worked so well there was no reason for me to consider any other sight options.
The new PCC is different. The barrel mounted aperture is very ineffective for me. I have a couple different low end red dots. Figured I'd try one, just to see. And it does improve things. On the range, as a novelty, it's fine. In the real world I would still remove it.
But for shooters who are comfortable with a red dot, this cheapo works so well, a higher level red dot could surely be the cats meow.