Benefits of Schema-Aware Processors

I imagine that this question has come up in the past, but I thought I'd 
ask anyway: What are the benefits of schema-aware XSL processors?

I'd like to learn more about the issue in both general terms and as it 
applies to the specific application I'm working on. I'm consulting with a 
firm that specializes in data warehousing for the insurance industry. We 
are using XML for a variety of document-production purposes (started with 
a dynamically generated data dictionary, now working on dynamically 
generating online help, etc.), but we are also exploring the xml->database 
and database->xml potential of XSL. What benefits might we derive from 
using a schema-aware-processor in such an environment?

Thanks.

Jay Bryant
Bryant Communication Services