I believe both of these assumptions to be true.
I have never been as comfortable and secure in the 11 years since returning to cycling as I am on this bike. I really nailed it when it came to buying the correct bike and modifying to compensate for my physical shortcomings. I truly believe that having a well fit bike with as you so eloquently put it "perfecting my position" gave me the confidence to reach farther.
But i was actually wondering if the stiffer frame adds to agility and handling ability or is there some other reason why Specialized might have put this frame on the higher end crosstrails?