The Airborne Carpe Diem titanium bike is about $2450 with 105 components. The Airborne Carpe Diem aluminum bike is about $1650 with 105 components. The Trek 520 is about $1100 with 105 components. The Cannondale T800 aluminum bike is about $1200 with Tiagra and other Shimano components. The Cannondale T2000 aluminum bike is about $1600 with Ultegra/105/XT and other Shimano components.
Personally, I think the lower priced of the above bikes gives the best value. All will provide the same functionality. All are strong enough. All have acceptable components. All will be irrelevant compared to the sights you see, people you meet, times you have, etc.
As for one being lighter, faster, etc. compared to the others, maybe. But all of them are trucks.
None of them compare to a very nice high end racing bike. The heavier frame, heavier fork, stable straight line steering, of a touring bike do not allow it to feel nimble and lively like a racing bike. These attributes allow it to carry weight over bad roads and stay in a straight line. Which is great for a touring bike.
I had a 1991 Trek 520 toruing bike and used it for many, many thousands of miles. It was a faithful truck. Heavy, stable, durable, pretty trouble free. I recently replaced the Trek 520 frame and fork with a better fitting Redline aluminum frame and fork. Most components transferred over. Even though the new frame and fork are several pounds lighter, the whole bike is still heavy and stable. And I am sure will provide faithful service in the future. I have other road racing bikes for fast and light riding.