This is my first rope, but I've had experience with a friend's Nomad 9.8 and a Metolius 9.8 as well. It seems to perform very similarly to the Nomad, but has much, much more sheath. It is just as supple with almost as much stretch to it. On a lead climb I haven't been able to notice the weight difference between the Xion and Nomad, but there isn't any multi-pitch near me, so I haven't tried that yet. The weight difference might be more noticeable then.
This rope truly shines in TR situations for me. I naturally prefer not to have it rub on anything, but if it does... well that's why there's so much sheath!