Lowercase a and e look very thick, and too big and round compared to other letters. This is especially noticeable at smaller font sizes.

In Fira Sans, the "a" and "d" are approximately the same width.

That doesn't appear to be the case here. The "a" almost looks stretched.
Lowercase a and e look very thick, and too big and round compared to other letters. This is especially noticeable at smaller font sizes.

In Fira Sans, the "a" and "d" are approximately the same width.

That doesn't appear to be the case here. The "a" almost looks stretched.