I have heard that mana racks are actually supposed to ring a bit, thereby adding to the sound. that would make them not so decent.
Not from what I’ve experienced, and definitely not as much as some racks I’ve used (including a reasonably expensive Stands Unique one that’s in my living room – looks nice but not the most effective).
The wall-mounted Mana table made a big difference to my LP12 – however that was due to footfall issues when it was on a rack so I think any wall-mount would have done the same.
I’ve heard some crazy suggestions from Mana accolytes and been to have a listen to some of their systems (where more money had been spent on the racks than on the kit it was supporting) and the guff about the “Mana Effect” seemed like a load of bollocks to me. One chap thought that a cheapo £100 CD-player would sound better on phase 4 Mana than a £1000 player on the floor. I went to listen to that system, taking a couple of my CD players, and it most certainly didn’t!
I am quite tempted to get rid of the Mana racks (but not the wall-shelf) though as it catches the dust and takes up loads of space. I’ve got a heavy Target rack in my bedroom system and to me that’s as good as the Mana racks and better looking.