In my experience the following things happens when using Ivy:
- It is easier to develop since the source code is often (always?) included in the libraries
- It is easier to release because there is a convention on how to store and upload artifacts/binaries
- Checkouts is faster because libraries is cached and disc usage on source repository server is less.
- It is easier to mange dependencies between own projects with clear definition of what version of project A works with what version of project B.
- Release notes and other documentation can be published and stored along side with binarys because it all is an artifact.
- It takes time to educate developers
- It requires some one with experience with Ivy to setup an initial environment (ivy.xml build.xml and a local corporate server to store and cache artifacts)
- When using Eclipse to build there will often be build errors due to poorly written plugins (will probably be better with IvyDE 2.1.0).