Wasn't the Windows 7 index extended to accommodate the faster hardware currently available? I used to enjoy building my own computer. However, I have discovered that I pay too much and get strange compatibility issues between a random selection of components.
With all benchmarks being equal, I would rather use one that was present on all windows machines. It also helps having a scale with a small range of possible outcomes. Something like 5.5, 4.2, 5.0 is easier to contend with than three comparable five digit numbers.

The review sites are good for reviewing individual components, and not so good at rating complete systems.