Been using Micro-Purl ICs for past 6 months and was quite pleased until I had a chance to audition NBS Monitor IVs. More of everything, particularly stage width and depth, great dimensionality of images, more "air" and layering, tighter focus and an even greater sense of "thereness." Fine balance and exceptional transparency. Nice wire, but then, ten times the cost of the Goertz. Can't beat Micro-Purl for the price, IMHO.