His ceiling is not higher than Bard. But he is much closer than Bard.
Buchholz is a 2-3 starter on a good team. I do think he will be a good pitcher at the major league level.
Bard has the stuff to be an ace starter or shut-down closer, but he is further behind a normal big college program pitcher normally would be at this point in his career.
"I do not think baseball of today is any better than it was 30 years ago... I still think Radbourne is the greatest of the pitchers." John Sullivan 1914-Old athletes never change.