Why Rebel Search is better?

• It features high-end search user interface with deep faceted refinements, document preview, visual hit count indicators & rich query language. It helps end users find information faster and for sure.
• It is the only real-time search engine for SharePoint. Every document you upload or modify appears in the search results immediately. No need to wait for a next incremental crawl.
• Licensing benefits. With Rebel Search you could get very powerful search solution running on Foundation. There is no need to buy SharePoint Enterprise CAL's (like you need for FAST) or even the SharePoint Server License. Depending on number of employees in your organization that could be a huge saving.
• Crawling is much faster with Rebel Search. That means you'll need less hardware to index effectively same number of documents (compared to standard search).
• Installation & maintenance is trivial. Carefully chosen configuration defaults and better architecture saves your system administrator from hardcore search issues troubleshooting inherent to built-in search.
• It is more extensible. No sealed classes, no inherited native code plus extensible pipeline & the fact that it is written completely in .Net gives you unmatched liberty to create customized search solutions. And do that easier & faster.