It's quite substantial. There's a few more photos below. It's hard to take photos of the inside but hopefully these will help.
As you can see there is a lining in the inside that actually helps keep the bass in place. It's quite padded. There's also the velcro neck support that holds the neck in place. The whole bag pretty much stands up on its own due to its mass. It doesn't flop in half like the cheap bags.
I also included a picture of one of the handles so you can see the quality of the rubberized material around it. Also there are feet like protection on the bottom of the bag not just exposed nylon material.
Hope this helps. For what its worth, I would have absolutely no concern about carrying my Zon in this bag. I'd carry any bass in this bag. I'm selling it because I have a rigid case for my Zon and really could use the money for other bass related items (though I'd be nice to keep the Zon soft case as a backup).
First pic shows the padded lining around the perimeter of the interior to protect sides of the instrument and prevent any extra movement.
Second pic shows padded velcro that holds the neck in place.
Third pic shows the rubberized handle.
Fourth pic shows the extra feet on the bottom instead of just exposed nylon fabric.
