Numbers and dead men tell no lies ... ... neither do they tell the truth.
If nobody's been recorded saying that before remember where you heard it first
Cost per unit of measure, be it dollars per gigabyte or apparent performance, is one way of expressing comparative value however it may not reflect the measure that's most important to your situation.
Perceived performance, heat, value, etc. includes intangibles or unmeasured characteristics that affects how we sense the individual or combined attributes as a whole. Reports seen above in this thread reflect greater perceived characteristics than the straight numbers would indicate.
Possible explanations for those discrepancies.
1. The benchmarked performances are not fully reflective of the real world.
2. With higher overall performance a smaller percentage difference is more noticeable.
The second point is quite significant as 10% of 100 is 10 points while 10% of 1000 is 100 points. A 10 point increase may not be noticeable while a 100 point increase may be very noticeable. At these performance levels percentage may not be the best measure to derive real value.