Are you kidding? One word: COUNTERBALANCERS. The modern triumph Bonneville engine family has them, as does EVERY modern parallel twin, such as the Yamaha TDM, MZ 1000S, Kawasaki ER6, and certainly this BMW 800. I bet it'll be smooth as silk. Remember, IT'S A BMW.
For what it's worth, I've ridden 197os era Kawaski KZ750 twins, and those are pretty smooth too.