When assessing a marble gangsaw, you must prioritize the stroke length and strokes per minute (SPM), as these directly impact cutting speed. A high-quality machine typically features a heavy-duty cast iron frame to minimize vibration, ensuring slab thickness consistency. Look for hydraulic tensioning systems for the diamond blades, which maintain optimal tension to prevent blade deviation. Additionally, verify the maximum block dimensions (Length x Width x Height) the machine can accommodate to ensure it fits your specific quarry blocks.