My problems were in fact with Java web services. There are different interpretations possible of the recent SOAP standards (or non-standards, as some are more de-facto than ratified) of smaal details as where to put type-info in the wsdl and if it is allowed to be redundant. This way sensible tooling is defied. Serving and consuming smaller services with light messages and shallow structure works mostly out of the box.

The going gets rough when people put half their strongly typed domain logic in the wsdl which has to be recereated on the other side. Hint: Collections != Arrays != Hashes

So, problaby not .NET but bloat related. Interoperability is a problem on all sides though.