http://spf13.com/post/soap-vs-rest
SOAP:
– Transport Independant (REST requires HTTP. SOAP can work on HTTP, SMTP, etc)
– Built in Error Handling
– Only XML
– Provides good ACID Transactions.
– Exposes pieces of application logic , Exposes operations
– Enterprise level security since it supports WS-Security
– Suitable for banking applications
REST
– Easier Learning Curve
– Efficient and Fast : Smaller message format
– Can use XML, JSON, etc
– REST gives access to named resources