The CSR pedals look to use a lot of plastic, even in structural areas, like the frame, pedal arms, and supports. The floorpan is metal, as are the pedal faces. Even though it's mostly plastic, the design appears robust. All three pedals use potentiometers to read position.
The CSR Elite pedals are of a similar design, but with metal in much more of the construction. While the frame is still plastic, the pedals are mounted in sturdy looking aluminum rails, and the pedal arms are steel. The brake pedal uses a load cell, which measures foot pressure to determine braking strength. This feels much more natural if you drive in real life. Races are won in the braking zones and my experiences with a load cell show it makes a big difference in braking precision and consistency.
The ClubSport Pedals are the big dogs. EVERYTHING is cast or machined aluminum, with steel rods tying it all together. They're really heavy duty. Emphasis on heavy. They use a load cell brake as well, and also use magnetic sensors for gas and clutch, which should last longer than potentiometers and should be more accurate. Overall, these pedals are really nice, and quite an improvement for only $50 more.
However, the CSR and CSR Elite benefit from being newer designs, and were conceived to be modular and more easily adjusted. There's an inversion kit on the way if you want suspended pedals for more of a road car design. There's a kit coming for the ClubSport pedals too, but as someone who has taken mine apart, I can say with confidence that inverting these will require some work.
