I tried mining at a High Risk RES - Metallic ring with Major rating. The chunks were all good 20% to 50% of Osmium, Pally, Plat, etc, but I really noticed far more chunks drop from a single Roid. Like 16 bits giving almost 7T of metal from one Roid. Sped the whole mining job up, the Limpet collectors really helped if you aim the hatch towards them.
I used my discount Clipper, big hold but still fast and agile with the Cargo hatch out full time.
Very promising boost to mining.