Marcinkiewicz 5*W (Standard) vs Yamaha CR-14A4aL
The Marcinkiewicz 5*W (Standard) has a wider cup diameter, the Marcinkiewicz 5*W (Standard) has a larger throat opening.
Cup Diameter
The Marcinkiewicz 5*W (Standard) has a cup diameter of 16.76 mm / 0.6598 in compared to 16.68 mm / 0.6567 in on the Yamaha CR-14A4aL — a difference of 0.08 mm / 0.0031 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a very shallow cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
The Marcinkiewicz 5*W (Standard) has a wider throat (3.91 mm / 0.1539 in vs 3.65 mm / 0.1437 in). A wider throat allows more air through, increasing volume and projection but reducing resistance.
Which is better?
Neither mouthpiece clearly dominates the other — the right choice depends on your embouchure, playing style, and the sound you're after. Try both if possible.