I have a large collection of White Label Promos (WLP)that I have purchased over the years. My view on the sound quality of these promos has changed with the passage of time.
Up until recently I felt the WLP were superior sonically but as my system got better and my record cleaning techniques improved, I use the Walker Prelude record cleaning system, careful listening comparisons with many original pressings of the same record indicate that the WLP do sound on average a little better than the average vinyl pressing but if you acquire 4-6 regular copies of that same record the Promo copy rarely wins in the shoot-out. I no longer look for promos of any kind anymore but instead just look for clean originals and evaluate each copy separately.
Johnny
Up until recently I felt the WLP were superior sonically but as my system got better and my record cleaning techniques improved, I use the Walker Prelude record cleaning system, careful listening comparisons with many original pressings of the same record indicate that the WLP do sound on average a little better than the average vinyl pressing but if you acquire 4-6 regular copies of that same record the Promo copy rarely wins in the shoot-out. I no longer look for promos of any kind anymore but instead just look for clean originals and evaluate each copy separately.
Johnny