It's just a different way of accomplishing the same thing - changing the moment of inertia of the balance wheel. As revolutionary as the copy makes it sound, the Durabalance it never really caught on in a big way.
Omega watches with a free sprung balance use screws on the perimeter of the balance wheel that are turned with a specific Omega tool:
This is a little out of focus but the photo wasn't really taken to show the screws, but they are there at the red arrows:
Other makers use different systems - Rolex uses the Microstella screw, and the tool is similar - the head of the screw is star shaped rather than square as on the Omega I showed:
As you can see here, these screws are on the inside of rim of the balance and not the outside - this reduces drag as the balance rotates. Also not shown is a second set of screws that are under the balance bridge in this photo - they are smaller and for finer adjustments:
Of course the other difference between the balance in this 3135 and an Omega 2500 or similar is that the Omega uses a flat balance spring, and the Rolex has an overcoil.
Earlier Rolex models like this Cal. 1575 had the Microstella screws on the outside of the rim, as well as screws for poising the balance:
Now the newest Omega balances (8500 and 9300 for example) have the screws on the inside of the wheel, and the head of the screw is like a Torx screw shape.
There are many different ways to create a system to adjust the moment of inertia of the balance wheel. These are balance wheels I photographed in the atelier of Romain Gauthier, and these have eccentric weights that are on posts that are rotated to adjust the inertia, similar in design to a Gyromax balance used by PP for example.
Hope this helps.
Cheers, Al
