This depends. Subclipse has superior support for checking out projects as maven projects – this is the sole reason we use Subclipse. Other than that, I have noticed subclipse bugs with syncing with SVN.
Subversive is much better at detecting new files to add to version control, and is also far superior with merging code from a branch, or even syncing with SVN (fewer bugs, etc.). So really, you should ask yourself what value you want. If you’re not using maven, I would definitely go for Subversive.