D-spaces can mislead a novice into correlating reciprocal space distances with real space distances. For CW instruments, the resolution functions are more complex, but not necessarily better. This is because better resolution is not always better. There is always a tradeoff between resolution and signal to noise. Besides, not all samples even have high Q peaks.
Different experiments demand different measurements.
One final comment. People tend to sweep imperfections under the rug. For very short wavelength machines, the asymmetry can be severe for the bulk of the pattern. Same is true for other types of aberrations. High resolution at low Q is handy for indexing, and is essential for tackling moderately complex magnetic structures with powder neutron data.