I used to think def the cabas, but after getting a few jumbos , I love them, they look great slung low messenger style and great carried with the strap doubled. I say get the jumbo, its a great bag for ever. Gorgeous, I love the new chain jumbos, my favorite!
Totally different bags and I don't think there is really comparing the two b/c they are so different.
Personally, I'd get the jumbo. Not only will it just continue to go up in price, I just love it. It is my favorite Chanel and gets almost daily use. Granted, I am not a fan of the Cabas whatsoever though so the choice is easy for me.
I have both, but if only allowed one I'd pick the jumbo. That will be a timeless bag whereas I do admit, the cabas is a bit more trendy. Also, the jumbo is more versatile IMO form day to night or dressy. The baby cabas is more only for day, at least for me.