The Aperta series are functionally similar to the original [pro sound] LR series only gussied up for the home market. The modular series is a way to extend the Isoacoustics isolation system to larger and heavier components.
The original LR series is made of ABS with steel tubes and rubber donuts. I don't expect that we would see an appreciable performance difference with the aluminum Aperta series. If anything, I would expect maybe a little less self-damping from the aluminum frames, but since they are sandwiched between the floor and a heavy speakers I think that the difference would be negligible.