I have owned both these bikes and think they are fairly crappy. The Sirrus is a low end road bike with flat bars and a harsh ride. The Crosstrail is more comfortable but just as low end. There are better bikes out there for the same or less money. I liked my brother's Trek 7.3fx but I am not sure what they go for.
It seems the big three ( Trek, Specialized and Cannondale) don't offer a lot for the money. I was happy with my Sirrus until I learned more. Now I would rather ride a mt bike with road tires or an old 1980's steel road bike over most of the new crap.
My advice is buy a good hardtail and get two sets of tires or wheels and swap out as needed.