Angellove14- the leather is definitely not too thin. It's a bit thicker than the Linea Pelle Dylan, if you're familiar with that line. It's not entirely smooth, but there's a subtle glaze to it. IMHO, this leather doesn't really translate in the brown sugar. Brown sugar seems like it needs to be more rugged. In the smog, however, I think this current texture seems to work better. It can be either casual or even a little more refined for more versatility.
I liked the whiskey in person for the same reason I liked smog. It can go casual or even a little more dressy. The whiskey has dark brass zippers, so it doesn't have the same contrast as the ones with the silver zippers. That's probably a matter of personal preference. If you're looking for the same leather as your Favorite Bookend, go for the burnt orange. Or, maybe order both to compare and return the one you don't want?
I'm carrying my smog for the first time today... it goes well with my skinny jeans, silk tunic, and silver jewelry. I'm happy because I know that if I wear ripped jeans and biker boots tomorrow, it will match as well. Overall, just a fantastic bag.