Besides the rough ride steep arms cause, the bigger issue is they barely let the axle move or lift up when a tire is trying to climb up and over an obstacle. Instead of a horizontal control arm that helps the axle and tire to climb obstacles more easily, steep control arms force the the entire Jeep to raise up instead while climbing an obstacle which really adds a lot of strain and difficulty to the process.
Hold your arm fairly horizontal then push your fingertips up 5" while holding your elbow stationary. Easy right? That's how easy it is for a tire to climb an obstacle with nearly horizontal control arms. Now hold your arm so your hand is pointing down at a steep nearly vertical angle and push up on your fingertips again. You'll then see the problem as this last test tends to lift your entire arm and elbow.
6" is just way too tall for short control arms, I'd at least remove the 2" BB. Not just for ride comfort reasons but to help your TJ perform better offroad.