Bybee Internal Speaker Bullets - user feedback?

I added a couple of Bybee Small Slipstream Purifiers on the RCA inputs in my amp and like the effect quite a bit.

Exchanging with Jack Bybee, he said the internal speaker bullets are, in his view, the best bang for buck of his products. That would be an expensive move for me as I would need 2 sets (they retail at about $800 per set).

Searching around A'gon, I was surprised to see little talk about these. Found a thread from 2008 discussing the Bybee Golden Goddess that apparently had just come out at the time. I believe the Internal Speaker Bullets are a DIY version of the Golden Goddess, that retails at $4200 (!!).

Would love to hear from those who tried them. In what kind of speakers? Was it worth it to you?

My speakers are B&W 804S. They were $4k when new...not anymore. I have to wonder if best bang for buck is to spend $1.6k on these Bybees or upgrade the speakers. The Bybees I can keep with me in future speaker upgrades, though.

Thank you!