With the release of Knights of the Fallen Empire rapidly approaching, I strongly encourage taking advantage of the 12x XP boost that is currently available to subscribers. More than likely, in order to progress into the new content, your character(s) will need to be level 60.
Bioware has announced that one free auto-level to 60 will be provided. However, I recommend doing this on a character that is not one of your primaries. Otherwise you will be missing out on a tremendous amount of backstory.
If you would like to group up to hammer through Makeb, Forged Alliances, Rishi, and Yavin, let me know!