In my experience, Zingerman's is overpriced and overrated. That isn't to say bad by any means, it probably still makes the cut for "great", but honestly I had better experiences at Bread Basket for much cheaper (with the caveats that this was years ago, and I've every expectation it'll vary depending on what you're getting).
http://www.zingermans.com/Product.aspx?ProductID=G-bac-3
From a great deli in Ann Arbor, MI