1.23:1 vs 1:1, performance, interchangeability?

Assuming your talking a Warner 1:1 compared to a PCM 1.23:1. There were several advantages listed at the time in the 89 brochure. I think the biggest one is that it allowed PCM to use standard rotation engines to turn right handed props since the trans was able to do the direction change as opposed to the Warner that always turns the same direction out as what goes in. The output on a PCM is down angled which does allow the engine to sit at a lower angle. They are interchangeable in the respect they use the same bolt pattern,but the PCM one is longer. It also uses more aluminum in its construction vs cast iron of the other.