I went through a phase where I spoke to people who develop numerous enterprise search engines (e.g. OpenText) out of about 20 interviews I think I found one that did actual evaluation work on their search engine. The rest of them figured it was more important to have 300+ 'integrations' to various data sources and didn't think the relevance of the results was much of a selling point.
Quality is harder to sell to enterprise customers when compared to feature lists. You have to check the right boxes and entertain the right ears to sell.
Being more useful than the others isn't as easy to quantify.
