We made a considerable time investment into axis in a project unrelated to OpenACS. We eventually discovered the overhead in using it was too high. In particular, we were unsuccessful in getting SOAP stubs to work from within applets without modifying the user's security settings (something related to the log4j integration). We ended up building light weight stubs using dom4j. It's a smaller jar deployment and we have complete control over the SOAP implementation. These client side issues ofcourse are unrelated to the server side SOAP components axis provides.
My interest in SOAP support for OpenACS is to bind RPC method invocation to package functionality on a limited scale. I intend to spec (and perhaps provide a light weight pseudo implementation) using existing components that accompany a typical OpenACS install. On the other hand, axis integration would yield a more robust and compliant alternative.