There is a discussion going on around superwash. I started tracking it through Webs FaceBook feed. I’ve linked to the original blog post that started it (or this round of it), as well as a more technical, thorough discussion of how superwash is created.
My purpose here is not to pass judgement on superwash. I do, however, feel there is value in being an informed consumer. My inclination has always been toward minimally-processed yarns. I like how minimally-processed yarn handles in a garment and I love the feel of lanolin. The colors allowed by superwash are stunning, though, and I usually put my minimally-processed hat off to the side when buying fingering-weight and sock yarn.
Over time I have allowed research, ethics and environmental concerns change my eating and other consumption patterns. It will be interesting to see how this information affects my future yarn purchases.