Just got my Inquisitor through 3 the other night. First character I've taken up that far, so I can't rightfully speak about other storylines, save my Warrior which is up to Voss so far.
What I really loved about the Inquisitor's storyline is how much it made you feel like you and your companions were going on this grand adventure throughout the galaxy. The inquisitor's story is very much removed from some of the larger events in the overall plot, but it is exactly because of this that you feel compelled to become a part of these larger events and move up the Sith food chain, so to speak. I was legitimately invested in my plot, going from just surviving to my ultimate goal
What I'm getting at here, that I haven't felt so much with other characters yet, is that the Inquisitor's journey to me really felt like a group effort. Not only did I have servants and a power base by the end of it, but I felt genuinely attached to each member of the crew.