Eclipse is pug-in based. It supports a lot of popular configuration management systems through this plug-in based system.
There are two different plugins available to use Subversion from Eclipse.
Which one to choose? It is a matter of personal taste. Any reasoning to justify one over the other would result into flame wars.
Both the plugins are developed, maintained and supported by the respective development teams. If you are an expert user of either of them, there is no need to switch. If you are just a beginner, either of them is fine.
Subclipse or Subversive
If you don’t know which feature is missing in either of the plug-in, you are not missing any thing.
If you know which feature you are missing, you have already made the choice.