The main aspects of these fins are:
1) Improved hydrodynamics with minimal weight increase
2) Minimum weight
3) Constant hydrodynamic in all depth/pressure levels thanks to incompressible rubber
4) Comfortable footpocket without loss of efficiency
5) Adjustable footpocket for various setups by different straps
6) Three stiffness versions: Soft, medium, hard
7) Extreme, full carbon fiber version (RX)
RX VERSUS R2
Carbon finer is harder and faster in recovery speed than fibreglass. As a result, RX fins are thinner and lighter than R2 because they use less material for the same stiffness. Although RX and R2 fins have the same exactly bending curve and stiffness , due to carbon recovery speed, RX are slightly more efficient.
Main difference is , that RX fins are stressed less for the same work output. As a result, RX fins are expected to keep their output properties for a longer period. So, if you are a professional, using your fins in daily basis, then RX is the recommended fin for you. RX blades are proven to remain the same, even after many years of extensive swimming.