There is a thread here (I am having problems inserting the URLs):
Home | Premier Designers | Chanel | The iridescent Caviar - Pros and cons
and this has also been discussed on the shopping Chanel forum "Shopping Spring 2013" recently.
Hope this helps. Wish I could link directly, but I've tried 5 times and that's my limit going back and forth to find the threads. Most say this material is very difficult to maintain, can't be cleaned, attracts dirt like a magnet (shoppers and SAs), and that it's not durable or for a bag that will be used regularly.