Yes Ron/Marigo has been around for a long, long time and makes interesting accessories and cables-some of which have been favorably reviewed over the years. Perhaps the name is/isn't unfortunate but Ron enjoys naming his products. I think his last feet were named bear claws or something like that
An audio product with the word "mystery" in the name infers that the designer has hit on something that really sounds good, but they don't know why. An audio product that has the word "magical" in the name could infer the designer knows what he did to achieve the sound he has obtained, but he just doesn't want to share it. Or, it could have the same meaning as "mystery." Either word used as part of the title of an audio product tends to make my B.S. meter peg to the right. If you designed something (and I don't care what it is) and it works great or sounds great, you ought to know why it works and/or sounds good and there should be no "mystery" about it.
And look, I don't know anything about the mystery feet and whether they 'sound' great or not. I just personally think the word "mystery" isn't such a great choice for an audio product's name. Other audiophiles may see the words "mystery" or "magical" in the title of an audio product and get all excited about it in a positive way. It's just not me.