What distinguished the Sierra and Cortina based XR Fords was the combination of performance, handling, comfort, roominess and practicality, and low operating costs, as parts are inexpensive and widely available. Other cars could provide some of the features at the expense of others. With these XR Fords, one could both have one's cake and eat it.
The above were larger versions of the Fiesta XR2s and Escort XR3s. They were the performance versions of their car lines. In addition to the XR versions, Ford offered the RS (Rallye Sport) versions of the Escort and later of the Sierra. Indeed, the RS's were even hotter than the XRs.