Hey Sherry!
The only drawback is the strap issue, as mentioned above. It's not a huge problem for me because I don't mind carrying a bag on the forearm and if I push it behind me when on the shoulder it will stay put for awhile. I love taking my GST to places like the nail or hair salon where I don't have to worry about it getting ruined and need to carry a lot of stuff, like magazines, water bottle, reading glasses, sunglasses, wallet, etc. The compartments are so handy, as well as the inside pockets and back pocket!
I have the old caviar and am not really sold on the new washed caviar in terms of the bag holding it's shape over the long-term. I don't really know if the GST in washed caviar is worth the new price point.