Believe it our not, as much as Red Dawn improved my Spica TC60/B&K system, the improvement wrought by SPM ICs was not subtle, quite obvious in fact. With the Alon V/Cary/Meitner system it was much more dramatic. Personally, I liked Red Dawn much better than Blue Heaven, both speaker & IC, fuller mids and bass. I think it's a fine cable. However, the SPM was better, and my new Quattro Fil is the best IC I've had in my system by a wide margin.