On the heels of the changes made to lowercase letters in Cantarell Bold, the outlines and spacing of the uppercase letters has also been reviewed and corrected. Some changes worth highlighting include the K, which now matches the design of the regular; the curves in the bowls of the P and R, which are much smoother now; and the widths and proportions of E and F.
Here’s a comparison of the old and new versions—
See related bug 707359.