I just tried some routes. It doesn't seem to give as much weight to cycle routes as ridethecity. E.g. Routing me along streets parallel to cycle routes.
I think this may be why I Iike it. As far as I can tell it ignores cycle routes, where as ride the city likes to get you on them.
My ideal cycle router would just ignore anything primary+, multi-lane or with a maxspeed greater than 50, and then just get me there the shortest way possible. I find the bbbike "avoid main roads" option generally works for me.
I'm yet to find a "cycle route" (at least in Sydney) that offers anything over the residential road running parallel to it. I'd much rather be guided by road width, traffic speed and traffic volume.
If cycle route implied some kind of cycle facility, then I'd be happy on a cycle route. The point (for me) of a cycle router, is if builds its own route from the infrastructure that exists on the ground.