Rome API allows developers to work with classes that closely resemble a particular syndication feed type. For example, the Channel class for RSS feeds and the Feed class for Atom feeds. All the Synd* classes, which leverage the RSS and Atom specific classes, are the bridge to go from one syndication type to another.
For day to day coding, we found ourselves using the Synd* classes (in com.sun.syndication.feed.synd, com.sun.syndication.feed.module and com.sun.syndication.io packages) as we need to do applications that understand the different syndication feed types. And it is much simpler to work with a higher and independent abstraction.