I worked in a photo store in the late 60's and a very finicky customer did some extensive testing comparing the EL Nikkor f/4 (this is before the 2.8 was marketed) against the Componon at 16x20, finally purchasing the Nikkor lens because the Componon was so much more expensive and no better. I bought the EL Nikkor f/4 myself and used it for many, many years. I finally came across a Nikkor 2.8 (a gift), and switched to it for the speed. I can't tell the difference in quality.
As others have suggested, if you are not satisfied with your prints, maybe you can post a scan or two. You could have other problems, including the lens deterioration.