I had the Apollo Messenger MM, which was original version of that messenger, I believe. It was a nice bag because it could hold a lot for work. However, the canvas cracked in the folds at the top of the bag, and it was totally heartbreaking because I LOVED that bag and it was a souvenir I brought back from Paris.
They've obviously fixed the design for the Odyssey, for as you can see there are no longer any folds in the canvas at the top. Still, it just looks to me like a bargain basement version of the Apollo.
There are still folds in the leather of the Discovery. I'm sure it will age much better than the Apollo, which was canvas, but my experience was so bad that I don't want anything to do with any bags of a similar design or that have such serious folds in them like the Discovery does and the Apollo did.