The fact that the search engine changed though is information. If the search engine is the same, maybe they had 490 mediocre experiences with the old one, and

The fact that the search engine changed though is information. If the search engine is the same, maybe they had 490 mediocre experiences with the old one, and then 10 better ones. Since it's the same search engine, they're going to average all of those together and say it sucks. If you tell them that the search engine is brand new, they'll reset their expectations and only look at the new data to make a judgment.