They are radically different designs. The AQ Diamond has silver conductors, the Decade has copper conductors. They are both very good cables in their class. That meaning the AQ Diamond, being silver, is quicker, cleaner and more transparent, while the TL Decade is smoother, warmer and fuller. The Decade is quick and clear, for a copper cable and the Diamond is smoother then some silver cables I've heard. That being said, only you know your musical tastes, and will have to ultimately decide whether you prefer the speed of the silver over the warmth of copper. Personally, I find that the ancillary equipment has a lot to do with how I feel about these cables. I prefer the AQ with tube equipment and the TL with solid state equipment.
