Love 'em! Super bright colors pop off of every, um, outfit (do dudes say that?) I wear. Comfy, not too sweaty when it gets hot out, and low stink factor so far. Owned a month or so, in hot 'ol Utah, wear them 3 - 5 days a week. As for the Hyper-color-change-technology; not so much. The color change happened as I was taking off the UPC stickers and stuff, but I've never seen it 'go' while wearing them. It's cool though, because I never read that they were supposed to do that. I just bought them 'cuz they're bright.