I have had this bag for over a year now, carry it every day, and it is still in terrific condition.  None of the zippers have broken, and the fabric still looks fresh and new.  It resists dirt beautifully.  I love all the pockets, and find the key fob to be particularly useful.

The one thing I don't like about it is the strap - I wish it was longer so it could be worn across the body.  However, I knew it was like that when I bought it, so I can't really say that is a mark against it.

I also bought the Rifton Messenger Bag, and it has a strap that can go across the body.  However, I found it a bit too small for all the stuff I want to lug around.  Zena wins, hands down.