Insulation comparisons should consider the entire assembly, not R-value alone.
Fiberglass
Fiberglass is widely available and familiar. Batts require careful fitting around framing, wiring and plumbing. Insulation should not be confused with the building’s air-control layer.
Mineral wool
Mineral wool is valued for thermal, fire and acoustic characteristics. Alandsons supplies Rockwool insulation where mineral wool fits the assembly and project goals.
Spray foam
Spray polyurethane foam can provide insulation and, depending on product and installation, contribute to air control. Open-cell and closed-cell products have different properties and can affect drying potential differently.
Which is best?
There is no universal winner. Define what each layer must accomplish, then select compatible materials and verify installation quality.