I'm finding the X10s to be great 'everyday' phones, very easy to just pick up with the iPod nano and go without giving much thought to it and wearing most of the day. They just don't call much attention to themselves, either sonically or physically, and provide a terrific listening experience for hours on end. Not sure how I feel about their $300+ price tag in a price/performance light, but not worried about it. I'm keeping 'em.
Coming from the S4s, the X10s just do everything a little cleaner without the bass bleed-over that often became tiring. They're just fun, extremely listenable, and smooth, with great bass power and depth...I roll now with these and/or my SE530s as a complimentary set of IEMs (more mid-centric ones).