I can see how your webbing is pinched and not allowed to slip by the piece on the right in the pictures. But, how does the piece on the left prevent the webbing from just sliding through?
You can buy them with adjustable sides (like on the right) or fixed (like on the left) for both sides, as you want.
If you have to sew the webbing to hold the piece on the left, or use tri-slides or something to thread the webbing through and then prevent it from slipping, then what is the real point in using one of these buckles?
They are almost indestructible, very low profile, lightweight, and very easy/quick to use.
At that point, you're depending on stitching or tri-slide friction, not the buckle.
Good stitching is as good or better than most buckles, I don't see it as a negative.
It looks like a 2-piece design where a traditional 1-piece buckle that requires no sewing or tri-slides, and only installs on one piece of webbing, instead of two, would be better.
(...)
I have changed all my rigs to these, which I really like:
http://www.leisurepro.com/p-xsscbu/xs-scuba-clear-path-buckle