High School English Teacher--I carry my LV Denim Baggy PM to work, and use my LV Perfo Speedy & Graffiti Pochette for all other non-work related, fun functions. For any other function, like the grocery store, or when I go somewhere that I know I don't want to be carrying a designer bag, I use my lower-end purses.
I have 3 LV purses, 2 The Sak purses (one black leather hobo & one fuschia metallic pink woven pochette), and loads of funky totes and book bags to carry student's files & other paperwork. I often wonder if I should invest in a good, sturdy, LV work bag, but I hate thinking about the kind of abuse that it would take.