Hi Kapil,
I'd suggest looking at using the HTTP API. Using this API will provide you with far greater flexibility as you will be able to easily write your own additions, in the form of web scripts, to meet your specific use cases.
The HTTP protocol is much 'lighter' than the WS and I'd expect there to far fewer compatibility issues with HTTP.
At Alfresco we currently tend to use our HTTP when developing remote clients (eg: office integration, portlets, flex applications all use web scripts extensively)
Hope this helps,
Roy