@OP What effect/s do you hear and where have you used them? That's a genuine question. I have a number of them that came in some pre owned gear. But I removed them as their adhesive had failed. I discovered they were there when I heard them rattling in the chassis! So I haven't auditioned them yet.
The Ultimate in Smoke and Mirrors? BUT...
Because I am an incurable tinkerer and my local distributor had a sale on, I recently purchased two Bybee "Quantum Signal Enhancer".
Has anybody else explored, with their own ears, this device? I'm not interested in theories, only personal experiences.
BTW, I've just ordered three more...
(Thank you in advance for your contribution.)