The chapter 6 path was intended to be a sufficient reward, but on reflection and based on player feedback it clearly isn't very compelling. This will be remedied in the next release, sorry.
Well, it'd be a tad unrealistic if every single conceivable path you could take yielded the same reward. Besides, you'll be getting an even better reward when you whack Renal yourself.
I just found that both of Maevar and the future replacement of Renal give no duties or reward - no 10500 gold and short sword like renal does - they give you bugger all.