Hi Ladies!
I went and tried on both bags today (large Black DS and Black GST) and here is my verdict....The Diamond stitch is a much more "casual" looking bag than the GST. The Diamond stitch is also more "formed" so when there is no stuffing in it and your arm pushes against it, the squared off "form" of the bag looks a little weird (you don't get this with the GST.) The GST is a much stiffer leather - the DS is softer.
Every SA I've talked to has encouraged me to get the GST over the DS since it is more "classic". I have to agree with them. And, the final opinion from my husband....he thought the Black DS looked more "masculine" than the GST. I loved the DS from all the photos I saw and it IS a great bag, so I am not dissing those who have it. It definitely looks more casual than the GST though, in my opinion.
I just got the Caviar & Pony Tote on sale (pic attached) and both hubby and SA's agreed that the bag I have was too similar to the DS...both being from "fashion" lines. Therefore, I should get the GST. Then of course, I had to start obsessing over the jumbo Caviar Flap! I think I will eventually end up getting that as my classic bag!
FYI - The Chanel Boutique at Millennia Mall in Orlando still has FOUR large Black Diamond Stitch Totes in case anyone wants one!