Bruno Tilz 211-T 4 vs Bruno Tilz 211-TS 6
The Bruno Tilz 211-TS 6 has a wider cup diameter, the Bruno Tilz 211-TS 6 has a larger throat opening.
Cup Diameter
The Bruno Tilz 211-TS 6 has a cup diameter of 18.50 mm / 0.7283 in compared to 17.50 mm / 0.6890 in on the Bruno Tilz 211-T 4 — a difference of 1.00 mm / 0.0394 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a deep cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
The Bruno Tilz 211-TS 6 has a wider throat (4.30 mm / 0.1693 in vs 4.00 mm / 0.1575 in). A wider throat allows more air through, increasing volume and projection but reducing resistance.
Which is better?
Both mouthpieces are categorized as "Catalog" — the physical dimensions above will determine which suits your embouchure and playing style better.