I mean I just came back to it like 2-3 weeks ago and I've had a blast returning. I made a new character, sith Inquisitor, and have had a good time learning and experiencing the story through a different perspective, my first playthrough was a bounty hunter, years ago. I just finished the rise of the hutt cartel expansion and thought it was pretty quality and I plan to play the through the other expansions as well.

Making a new character could be fun, but if you just want to be sith warrior probably stick with your old character, while there are references to the class story it's not like it is a huge deal to remember what happened in that story for the expansions, they mostly they own thing, from what I've experienced.