What are the advantages of using Apache CXF over Apache Axis and vice versa?
Keep in mind, I'm completely biased (PMC Chair of CXF), but my thoughts:
From a strictly "can the project do what I need it to do" perspective, both are pretty equivalent. There some "edge case" things that CXF can do that Axis 2 cannot and vice versa. But for 90% of the use cases, either will work fine.
Thus, it comes down to a bunch of other things other than "check box features".
API - CXF pushes "standards based" API's (JAX-WS compliant) whereas Axis2 general goes toward proprietary things. That said, even CXF may require uses of proprietary API's to configure/control various things outside the JAX-WS spec. For REST, CXF also uses standard API's (JAX-RS compliant) instead of proprietary things. (Yes, I'm aware of the JAX-WS runtime in Axis2, but the tooling and docs and everything doesn't target it)
Community aspects and supportability - CXF prides itself on responding to issues and making "fixpacks" available to users. CXF did 12 fixpacks for 2.0.x (released two years ago, so about every 2 months), 6 fixpacks to 2.1.x, and now 3 for 2.2.x. Axis2 doesn't really "support" older versions. Unless a "critical" issue is hit, you may need to wait till the next big release (they average about every 9-10 months or so) to get fixes. (although, with either, you can grab the source code and patch/fix yourself. Gotta love open source.)
Integration - CXF has much better Spring integration if you use Spring. All the configuration and such is done through Spring. Also, people tend to consider CXF as more "embeddable" (I've never looked at Axis2 from this perspective) into other applications. Not sure if things like that matter to you.
Performance - they both perform very well. I think Axis2's proprietary ADB databinding is a bit faster than CXF, but if you use JAXB (standards based API's again), CXF is a bit faster. When using more complex scenarios like WS-Security, the underlying security "engine" (WSS4J) is the same for both so the performance is completely comparable.
Not sure if that answers the question at all. Hope it at least provides some information.
:-)
Dan