That's the very feature combination I most appreciate in the Specialist.
The close fit between the metal buckle and the polymer belt material makes the stability of the "closed" belt almost absolute, since it's far more dependent on friction than on the tail staying in place via hook-and-loop adhesion.
It takes a little extra trouble to thread the belt through the metal buckle, but if you like the belt tight, as I do (for enhanced concealment in AIWB), it provides for a more solid lock than does the polymer buckle, which, while looser and quicker to thread, doesn't grab the belt tail as strongly, and it can slip backward prior to engaging the hook-and-loop, which never happens with the metal buckle.
To each his own, of course.
I have several examples of the belts with both buckle types, but I wear the metal buckle ones 90% of the time.