I had used some when I played a double bass direct to the mixer.
Now, that I play acoustic guitar live, I found the sound to be in a certain way, kind of irregular (not something very noticeable).
So, having a good experience with these, decided to try them on the guitar, and it really gives me what I want which is a kind of tighter sound, without much of a change on the tone.
The packaging is good, and very resistant.
Runs on phantom with no problem, but you can run it on a 9v battery.
I've used on some occasions BBSs and I don't think I hear that much difference just like that.
Very good for the price.