sorry for my late response.
Oh sure there is. MTOM is more integrated with the WSE communication stack,
and it provides better security to the binary data that is transferred.
Also there is an optimization option that base64 encodes very small binary
messages not to include the burden of sending the actual binary data in
different XOP part.
Unfortunately, AFAIK only WSE2.0 (VS.NET 2003 - .NET v1.1) is capable of
consuming DIME enabled applications.
MVP, MCT, MCSD.NET Early Achiever