So far, with the Ampohm polyester caps, after just 48 hours in my preamp outputs, they are showing real promise. Better highs and a more "see-through" quality to the music. I want them to break in some more before I give my final take. If they end up winning my heart, I'll be selling my pair of 4.7uf Duelund VSF coppers for a great deal. I'm beginning to think that the Duelunds are best suited for speaker cross-overs. Stay tuned.