Fructose interferes with glucose use and regulation. The real comparison to be made is between normal corn syrup (only glucose) and HFCS (about half fructose), not sugar (about half fructose).
When using crude tools to evaluate metabolism like the glycemic index, which only considers blood glucose, it appears that fructose is better. The modern Western diet leads to obesity, diabetes, and fatty liver disease (NAFLD) because fructose metabolism collides with lipid metabolism in the liver.