Just wanted to mention I am using JAX-WS 2.0 for my web service layer. Even though it is a reference implementation it still has been fast compared to axis. The important thing to know about Web Service layers for performance are:
1. Use fast infoset. 2. Use Document literal 3. Use primatives and array of primatives instead of collections 4. Keep messages small (below 1500 bytes)
I would only use Web Service layer for B to B but would advise for large objects that are returned from a Web Service to use RMI if used inside a company.