Most commercial diffusers are designed for looks rather than measurable acoustic performance

Evidence

These devices now appear in countless versions, many of which are clearly designed for visual appeal rather than acoustical performance. It can always be claimed that irregular surfaces scatter sound, but the reality is that some designs do it much better than others. If one cares about the performance, it will be difficult to find meaningful specifications because they take time and money to measure. Visual appeal is powerful, and frankly, almost any irregular surface is sufficient to address flutter echoes. — Toole, Floyd E, Sound reproduction- the acoustics and…, 1389

Categorization

• SEED: A skeptical-buyer’s-guide angle: how visual marketing outruns measured acoustic performance in a whole consumer category — parallels Bose/cable/hi-fi snake-oil critiques.
• QUESTION: Which diffuser designs actually publish meaningful specs? Worth chasing a benchmark source (Cox & D’Antonio is cited).
• corroborated: 2 independent passages support this claim — Toole, Floyd E, Sound reproduction- the acoustics and…, 1389