I've ridden both and since I will be riding mostly on paved roads I went for the Sirrus. The sales person at the LBS also mentioned that I might run out of gears with the crosstrail whereas it would not be the case with the Sirrus. In retrospect I'm really happy that I went for the Sirrus and not for the Crosstrail, also because I already have a mountainbike with semi-slick tires.