Hmm. That's a hard one to answer, the electric drivetrain is very smooth, but the suspension (at least the smart air suspension) is 'tight'. I'm running 20" wheels so that should get me the smoother ride. It's definitely less harsh than my Prius v with 17" wheels but I'd say not as smooth as a Cadillac land yacht and probably closer to my buddy's BMW, but, as I said, the smoother drive of the electric tends to soften it.
Where are you located? I'd be happy to offer a test ride.