Both machines are fast around 67 mph. The VXR will be a little more bouncy and wetter ride, because the hull is flatter. The SHO will be more stable in the rough stuff and it will also burned significantly more fuel because of the supercharged engine.
For younger single riders, I would consider the VXR. For more of a family machine I would skip the SHO and look at the FX HO instead. You get a very similar ride, better gas mileage, and just a few miles an hour lower speed.