Short answer: YES!
Good lenses make a huge difference in image quality, even at f/8.
But of course rarely is anything black and white. For example, depending on the camera you are using, the differences may or may not be as noticeable to you. Many of the L lenses are much better in the corners with less distortion, less vignetting, and better sharpness, but crop sensor cameras only use the center of the lens where the difference can be small. If you are using a full frame camera with higher resolution such as the 5D or 1Ds Mark II you will definitely see the difference.
Also, you may not notice significant differences if you only make small prints.