I think the issue of clamps or weights is too equipment-specific to permit generalized recommendations. In my case, a number of years ago when I used a VPI 19 Mk3, I thought the stock clamp improved the sound without any negatives, so I used it all the time. When I switched to a Galibier table, I started out with the heavy PVC platter (14 lbs) and I spent many hours experimenting with the 6 lb weight (appropriately named the Anvil) that came with it. The Anvil is an aluminum weight that is filled with lead shot and oil. What I found is that the Anvil consistently did some very good things but also some not-so-good things. In other words, there were tradeoffs when using it. To complicate matters further, the type of reflex washer made a significant difference as well. On balance, I usually ended up using the Anvil but I was always aware that I was sacrificing in some areas.
Fortunately, this all changed when I upgraded the platter to what Thom Mackris now calls the Gavia platter. This is an even heavier (32 lbs) aluminum platter filled with lead shot, oil and PVC damping materials and topped off with a graphite top plate. This new platter sounds much better than the old PVC platter but it also consistently sounds better when used bareback, i.e. without the Anvil or reflex washer. This makes life much simpler.
So the takeaway as far as I'm concerned is that it is difficult to generalize about clamps. With some equipment and to some users, they may be an overall improvement, but to others not. You just have to try it for yourself and reach your own conclusion. One thing can be stated unequivocally---a record weight or clamp does change the sound. Anyone who says differently hasn't listened carefully enough in my opinion.
Fortunately, this all changed when I upgraded the platter to what Thom Mackris now calls the Gavia platter. This is an even heavier (32 lbs) aluminum platter filled with lead shot, oil and PVC damping materials and topped off with a graphite top plate. This new platter sounds much better than the old PVC platter but it also consistently sounds better when used bareback, i.e. without the Anvil or reflex washer. This makes life much simpler.
So the takeaway as far as I'm concerned is that it is difficult to generalize about clamps. With some equipment and to some users, they may be an overall improvement, but to others not. You just have to try it for yourself and reach your own conclusion. One thing can be stated unequivocally---a record weight or clamp does change the sound. Anyone who says differently hasn't listened carefully enough in my opinion.