These shoes are awesome for my long distance runs on pavement, with *amazing* airflow that keeps my feet nice and dry (except when I step in a puddle!).  But when I took them out on a grassy hill for an XC workout, stuff got stuck in the bottom of the shoes and I could feel every little bump in the course.  So they're great if you're a city runner who doesn't really care about running in the grass.  But if you're an XC kind of girl, I wouldn't recommend them.
Mine are also approximately a half size too large, so buy down a size.