With my copy, its performance & image quality is impressing and not that different from 35L. In situation that I can use both lens I don't hesitate to chose 24L because of perspective that 35L can't. Actually, if we want wider lens, 24L does't need to be compared to 35L. And at closet focusing distance, bokeh is as beautiful as 85L & 35L.
Like other fast lens, using at wide aperture, we must take very good care of focusing to prevent soft image.
My 24-70 f/2.8L was sold six months ago and, yes, I work harder due to no flexibility of zoom. However, like others, the more I use, the more I love this lens.