Thanks Brad for the neato pics. Up to date pics explain everything without a whole lot of words.
I’m really into replaceable belt buckles because over the years I have occasionally stepped on one during a trip with this result—

So having a spare hipbelt buckle is vital. I think the new SO hipbelt system fixes this problem—field replaceable.
As far as the gatekeepers and web loops, these loops can accommodate the pictured side release female buckle by getting the loop to slide inside—and then removing the GK and adding the male SR buckle (?Do I have that right?).
But yes, I was raised on Fastex side release buckles (my beloved North Face 1980 pack). Fool proof, strong, that reassuring CLICK—and easy with mittens at Zero degrees. Gatekeepers at 0F? Have fun, boys. Imagine that the web loop is frozen solid because it got soaked yesterday and this morning it’s frozen solid and stiff because at midnight the temps dipped to 10F. Now try to remove/attach the half dozen GKs.
I know all about wet webbing which freezes solid—and the cursing which comes when trying to fumble with such intricate gear using mittens etc.