jcoop--I can't decide!
I love, love, love the grey. Of course you know this because I bought the bag in grey.
I really didn't think I'd be too concerned with it getting dirty, but that changed a little when I took it out this weekend. Everywhere I went there was tons of the gunk that comes from the sand/salt/dirt they put on the roads after snow. It gets on your car, your clothes, in your garage, in your house. And a little got on my bag--I almost screamed!! It came right off, but I think if I had the cognac there wouldn't be an issue.
So I would say that I vote for the cognac because of the potential getting dirty issue, but I can't!!! There is something about the grey that still draws me in. lol--I still vote grey!!
That being said, they are both lovely, so I think you can't go wrong!!