I use Maven, not just for build, I also use their release/dist plugin.
In a pair of commands I can have code that was in a source control to build, package and release.
The release plugin handles updating the version numbers, dist handles how to put everything together and zip it.
Ant looks hard when compared to Maven. Sure there is a learning curve with Maven, but reading a pom.xml is far easier than reading a build.xml.
Maven needs to be far less verbose.