Went to the LV shop to try the Tulum sizes in person, and boy am I glad I did. I really liked the size of the PM, but then my fiance reminded me to walk across the store with it to be sure the strap wouldn't slip off my shoulder. It did...I was sad. I tried the GM, with the strap up as short as it would go, and it wasn't much better. I was sadder. I tried the Highbury...which was worse! I even checked out the Hudson PM, but that was considerably smaller. Then, bless his little engineer-heart, my fiance suggested trying the Tulum GM with the strap a little longer....something about "adjusting the fulcrum point." I lengthened the strap just a couple of notches, and lo and behold...no more slipping! It was perfect! I looked in the mirror and it's really not too large for my proportions, and the canvas is nice and soft. I took a deep breath, accepted the slightly higher price difference between the PM and GM...and brought the Tulum GM home with me! I've only gone out once since then, but I can easily say this is one of the most comfortable bags I have ever worn. The soft shape makes it sort of conform to my body, and if I ever need to carry it as a messenger bag, I'll be able to. I normally wait at least a few days, but I feel so sure about my longterm compatibility with the Tulum that I've already taken her outside and Shining-Monkeyed her. Yay for finding my favorite bag - I'm a very happy girl! I also want to say a BIG THANK-YOU to LVixen, who bought my Batignolles Horizontal and made the Tulum possible. You rock!