At the core of the Audax is the full CrMo frame, with double butted tubes, providing a light and strong endurance road machine. The natural dampening characteristics of the steel take out a lot of the road "buzz" letting your arms relax as you eat up the miles.
The dropouts and seat stays are ready for a rear rack, and, thanks to the longer chainstays, there is plenty of heel clearance when panniers are mounted. Up front, the taller headtube is a little bit easier on the back muscles, and the longer trail length means the steering is far less "nervous" than on a race bike.
Thanks to the Shimano 105 compact chainset and 11-28t cassette, it does not matter where your Audax takes you, there are plenty of gears to climb those hills. If the weather turns nasty as it often can, the fenders become invaluable and indeed a new best friend.