Hot on the heels of the previous comparison post (12 speed vs 11 speed): Instead of comparing within the same category (XTR to XTR, or XTR to Deore XT), I can also compare across categories, from MTB to Road. This kind of cross-category comparison is usually not meaningful, as they have very different intended usage. For example, it is not so useful to compare shifters, derailleurs or cranksets across categories.
For cassettes, cross-category comparisons are possible, because the design and intended usage is more similar. In fact, old MTB cassettes (up to 42T sprocket) has becomes the new gravel cassettes. A more extreme case is that older MTB cassette ratios such as 11-34T for a 2x10 or 3x10 speed MTB drivetrain, is now found on road bike cassettes nowadays.
Today's comparison will be rather brief, as the details of each cassette can be found in their respective posts. This time, the comparison is between two 12 speed cassettes. The XTR 10-51T CS-M9101 vs Dura-Ace 11-30T CS-R9200.
Large 10-51T 12 speed cassette, the XTR CS-M9101. It is also available in a tighter 10-45T specification.
Dura-Ace 12 speed cassette, CS-R9200 is available in 11-30T and 11-34T versions.