Curry 3 C. vs Marcinkiewicz 4S
The Marcinkiewicz 4S has a wider cup diameter, the Marcinkiewicz 4S has a larger throat opening.
Cup Diameter
The Marcinkiewicz 4S has a cup diameter of 17.20 mm / 0.6772 in compared to 16.89 mm / 0.6650 in on the Curry 3 C. — a difference of 0.31 mm / 0.0122 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a medium cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
The Marcinkiewicz 4S has a wider throat (3.73 mm / 0.1469 in vs 3.70 mm / 0.1455 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.