Don't know about the technical details, but I also tried the Crescent and found it to be just as comfortable as the Bora. I eventually settled on the Bora because I felt the fabric was much superior (I haven't had to use a pack cover with it, even in heavy rain). Also, I believe the hydration system in the Crescent was located in the "brain" compartment of the pack, which I didn't like - thought it may have since changed.

Plus I'm not sure if the Crescent is available in charcoal.