Because of the inability to place the rear element closer to the film plane (the mirror gets in the way) RFs are touted as having superior wide-angle results. We know that this is so in theory and that compromises had (and still have?) to be made with optical formulas in order to 'compensate and correct'.

But, I ask, is this still so, with computer technology determining, most efficiently, the lens formulas of today? In other words, is a top flight Nikon wide angle (say 20, 24, of 28) inferior in any way to a Leica RF lens of the same focal length? - David Lyga