Ask HN: Have you used MarkLogic Server and what was your experiences?

I'm considering using MarkLogic Server as a backend for searching XML documents for an upcoming project. I am wondering if anyone here has had an experiences with it and what they thought?<p>I'm considering deploying it as an Amazon EC2 instance and then indexing my documents into it from S3. Has anyone tried this?<p>Link: http://www.marklogic.com/products/marklogic-server.html