The problem with flat files is that you are relying on the copies of files working compared to say talking to a central server. Advantage with central server is that you only have to make sure that one thing is working, whereas with flat files I store them on various servers and then pull them in.

The database means that it is easy to present the information via the web and all the queries are done in this.

The real problem faced is getting the information from the clients (spread across multiple sites/countries) to a central location. Information could be as little as 1k in a file so I am guessing im looking for some super efficient way to send this .