They run like normal NPs and are comfortable. Mind you, I only tried one on during the CL trunk show last year, but from what I remember they were similar to the NP IMO.
Mine are coming any day. I had tried it on and they felt great, but I have not worn for more than a few minutes in the store. As for size, I the best for me was my np/vp size which is 1/2 size up from my american size.