The R21 is the value flagship here: 21 Nm against the Podium DD1's 20, cheaper, and higher on our rubric. It proved MOZA could compete at the high end before the Ultra line existed. The Podium DD1's counter is Xbox support and the Fanatec ecosystem, which the MOZA cannot match.
So on PC, chasing value, the R21 is the pick - more torque, lower price, higher score. If you need Xbox or want the Fanatec rim catalogue, the Podium DD1 earns its slight premium. Platform and ecosystem decide it more than raw performance.