I only have about 50 hours on my Deep Core and I am very impressed so far! The soundstage has grown quite a bit, depth wise and horizontally, while the bass response has also improved. My system is quieter and low leveling listening has become even more satisfying. Hard to fathom right now what things will sound like at the 500 hour mark. Thus far, I prefer the knob turned furthest to the left, as this gives the best response. This is a keeper!