IMO fault\error\exception (which ever you like to call it) is never nice to look at in the 'real' world of application development, whether it be a exception handling strategy like the enterprise library exception handling block, detailed error messages\codes or multiple 'catch' statements.

Just as long as you decide on a strategy you can justify and use it every where then it should be ok.

As I & others have stated above I believe you shouldn't throw exceptions from a service - detailed error codes\messages should be returned in the response message, only the communication infrastructure (e.g. SOAP via HTTP) should throw exceptions.