I bought a pair and really wanted to like them, but ended up preferring the sound without them.
Tried them in every type of position but they always seemed to add too much mid and high frequency energy and soundstage and imaging suffered.
I have a fairly high resolution analogue and digital front end with all tube amplification:
Avantgarde Duo's, Benz LP S-MR/Clearaudio Universal arm, Ortofon Anna/Graham Phantom, Clearaudio Innovation TT, Zesto Andros Phono Stage, Wadia 16i, Oppo 105 for SACD, Conrad Johnson 16LS pre, Cary V-12 amp, Synergistic Ref cabling.
They definately made a difference in sound, but not for the better in my system.
It really mystified me given all the positive reviews I've read about them improving the sound stage as it had the opposite for me.