I hear ya there! I just rented one for my weekend in San Diego and the owners warned about the solid wheel and the wind effects. I definitely noticed it pull a little bit in the wind, but the weight of the bike seems to keep it pretty well in check. Of course I didn´t see anything near the 50 mph you were talking about. I bet a spoke wheel would help bigtime. But the solid looks so COOL.
In all, I was hugely impressed with this bike. Plenty of torque and ridiculous high end, certainly by Harley standards. 9k redline with a big VTwin??! What´s not to like there. This bike rocks.