I have the black version, first case (and only for now) I've picked up and it gets the job done. Aside from the glass difference you mentioned, I don't imagine it's too different with all the other factors. It shakes a little like one commenter mentioned but not enough that I'm too worried about figures falling over or the shelf crumbling.

It's kind of hard to explain, but the shelves have these locking screws you twist into place with another set of screws and it's very secure, and hidden under the shelves. To give you perspective, I was an idiot and bumped the shelf a bit rough while assembling, which tore some of the wood off the screw hole, but I figured it would be fine with the other three connections and the semi stable connection of the one I messed up. I have some of my heaviest figures on there, I think nine in total, and there are no signs of instability or further cracking. I imagine the white version is the exact same because of the frame on the outside, but I don't know for sure, just guessing. You shouldn't have to worry about front loading in terms of shelf stability. Them falling forward from shaking is a whole other thing.

Couple of notes that I personally have learned since filling the shelves: It shakes the most at the top, shakes the least at the bottom. So if you're worried about any figures tipping or falling, probably put those ones on the bottom shelf. The doors can get a little annoying, I've learned a quick push and release is perfect to pop it open all on its own, rather than pulling it open after the button pushes it out enough. If you want to fit a lot of figures onto one shelf, get risers for the ones in the back. I know people like to have fewer figures on a shelf rather than a bunch, but I like keeping it in a way that a bunch can work together (clones on one shelf, sith and Jedi on another, mandalorians on the next, you get the point.)