I used to hate Longchamps or wonder what all the fuss was about. Last April, my friends and I chipped in and bought a black one for another friend's birthday, since she really wanted one. After seeing her use it for school or whatever on a day-to-day basis, I thought it wasn't so bad.
So of course, I ended up getting one myself in November, and have been in love with it (until I got my MBMJ Dr. Q Hillier Hobo). I ended up ditching my backpack or a black tote I had from Target (Via Spiga-inspired, though I didn't know it at the time) to carry the Pliage to class.
While I usually love structure in a bag, or at least the bottom, I have gotten used to the slouch of the Pliage. I think I stayed away for a long time because of the slouch/sag/unstructuredness of the Pliage, but it's grown on my since I've been stuffing it with all my crap for school.
I had a friend comment on it when she saw me wearing it, saying, "Oh, that's a bag that my mom has...What's so great about it?" I told her that I used to wonder too, but that it's really functional if you need a bag to throw stuff in.
As a student, the Longchamp has been a great replacement for the old school book bag I used to carry. It fits a great amount into (more than I ever imagined it would) and still looks semi-classy but not ostentatious. All in all, I think it's a great bag for certain purposes, but if you're looking to be fashionable/chic, this might not be the bag for you? But to each their own!
I totally agree with you! The large size is perfect for carrying school-stuff in, or using as an overnight/travel bag.
The only thing I wouldn't use it for is a date, dressy-casual restaurant, or formal event.