I only have the 12, I feel like it's the best size for my petite frame. The 10 seemed a little too small and doesn't have any slouch factor. The 12 has just a little bit of slouch which I prefer personally, and not too big.Curious as to those who have multiple sizes, which do you prefer and why? I started with 2 size 10 bags and thought that size was perfect for me but when I got a 12 I’m finding that I love that size more than 10. Getting in and out of the bag with more ease because of the bigger opening has won me over.