I have used my copper TTW outer ring with a variety of decks. I have used it with and without center weights. Here are my thoughts. The outer ring does help with records that have minor warps. I can see the difference with less tonearm movement and less pumping of the woofers on the first and second track of warped records where the deviation tends to be greatest. On every record I can hear a difference. Without the ring, in general, the sound is more vibrant and "alive" on first blush but at the loss of inner detail and firm low bass that sound true to tone. After trying dozens of center weights with my VPI Prime and highly modded TD124 with a Reed 3P, I have a favorite with both; the original Thorens Chrome and rubber O-ring classic. But I have several custom made wood center weights (very tall and high-mass) and they sound great with the outer ring as well. Everything makes a difference-mat, center weight or clamp, and outer ring or no outer ring. Whether they are positive or lateral differences is up to the listener. I've settled on the Gem Dandy cork and rubber mat on my VPI and a carbon fiber mat on my Thorens. I'm pretty clumsy and I have never come close to taking out my stylus/cantilever with my outer ring. So what I am trying to say is this; the main benefit of an outer ring IMHO is to damp and absorb energy dissipated across the record surface by the stylus in the groove. I can't prove this is what the outer record does, but it makes perfect sense and from what I hear, the theory behind the outer ring and the benefit coincide. And one more thing; don't even think about an outer ring with a 9" arm (if someone has succeeded with a 9" arm, I am sure I will hear about it). Most times, you will need a 10.5 or better yet a 12" arm so that there is plenty of clearance between the outer edge of the ring and the tonearm column.