Cabas Piano Sag?

as far as i can see, it doesn't. my mom's is about 4 years old and its still holding its shape. mine is 3 years old and it has a great patina now.

i guess the only softening is the handles from use.
 
No sagging on mine. I've had it for about 3 years, too. I really like the structure on the bag.

I do notice in pictures that the Vavin PM start to sag at the bottom.
 
I've had mine just under a year and no sagging, but she doesn't get daily use either. Only change I've had is the patina process...looking great!