I think that looks about right, but your experience will vary depending on how you try to overcome the gearing humps. If you have alts feeding you gear and don’t listen to the conversations for the quests, then you could probably rush through in around 16-18 hours.
In my case, I’ve spent more time on planets like Hoth or Belsavis in order to keep my gear (and that of my companion) a bit more up to date; I’ve also listened to every conversation, because I enjoy the story.
I’m looking at about 28-30 hours, at a guess, so you’re pretty much bang in the middle from what I can tell.