What is usually missing during demos is a focused solution which solves the business problems that have brought the potential client to see what the demo is all about. They have most likely seen the same vanilla demo over and over again if they are being pitch an xCP solution.
What the client is looking for is your understanding of their problems, that you've been there. Some can see the potential of the demo to solve their problems. Others will want a business analyst to give the details of how the requirements of the business will be matched with the functionality of the software.
The problem is that every business is unique and are seeking software to fix issues with their processes or content management or collaboration. They have gone to the trade shows, they have read the books, they want to move up in their companies. Now you have to somehow convince them that the software can get them their promotion, or at least make them look good.
If you have a fast talking sales guy in the room make sure you get a feel quickly if the clients are comfortable with his energy and fluff. If not, have the demo talk. If that doesn't work, bring out the business analyst who has been in the trenches. If they chew him up, walk away.