We have all agreed that using Adobe Experience Manager for search on a site is probably not the best way to do it—No one likes to use it. In the past, the options available have been Google or Search & Promote. Google Search Appliance and Google Site Search are being mothballed, and Search & Promote seems to be treated like the red-headed stepchild in the Marketing Cloud. Some have chosen to start using Solr as a replacement. And it is a good option. Question is, how do you use it? We have seen two ways: Adobe & Headwire.
The Headwire method, as found on their AEM Solr Search page, is best described as a Push. It pushes content from AEM into Solr as AEM content authors click the Publish button in the Author instance. The Adobe method, as outlined in their HelpX article “Integrating Solr with Adobe Experience Manager”, is best described as a crawl (similar to Google). It continues to crawl/index your site and then uses that index to search. Both are very viable options, in the end it boils down to the way you want to do things. Good luck, with either avenue you decide is best for you.