Advantage of using BizTalk to define a webservice

Well, BizTalk gives you message tracking, reporting, rules engine, and BAM. If you are not using any of those, not really a need to update an existing web service.

Unless you are making a move to BizTalk and want all your services written the same using BizTalk for Admin and Maintenance reasons.

The one really good thing about web services using BizTalk is its rather easy for someone to look at the underlying Orchestration and know what’s going on. The same can not be said about looking at web service code.

Hope this helps.