I have the large one in red. I always use it for travel, it's an amazing carry on bag and I also use it as an overnight bag. When I come home from college for a weekend, I'll pack all my clothes and other necessities in there. On the weekends during school, I like to go into the city and study for a few hours I'll use my bag and carry my laptop and bring my lighter books and materials.
Also, if my friends and I go buy alcohol, we'll stuff it all into my Longchamp so we don't look suspicious carrying around black plastic bags, lol.