Will a sports bike or a cruiser ride smoother on the highway?

which bike would provide a more FUN experience at speeds around 50–70mph? i don’t want to be shaking and vibrating. I’m torn between Kawasaki Vulcan 800 or a Suzuki GSXR 600. i want a cruiser to be more relaxed, but if the ride isn’t as smooth or enjoyable I’d sacrifice comfort for the ride. any suggestions…even another bike? thanks!!