Google was marginally better in popular searches and
significantly better for tail searches. This is a big reason why it flourished with the technical and student crowd in earlier days because those exceedingly rare sub-sub-topics would get surfaced higher in the rankings. For the esoteric topics Yahoo didn't have it in catalog and Altavista maybe had it but it was on page 86. Even before spelling correction and dozens of other useful search features were added, it was tail search and finding what you were looking for sooner. Serving speed, too, but perhaps that was more subtle for some.
Metasearch only helps recall. It won't help precision, the metasearch still needs to rank the aggregate results.
