Well, I did say I like Garcia-Lopez's covers on the Superman books, and his work on the DC COMICS PRESENTS books.

I was just looking at his covers on SUPERMAN FAMILY (Garcia-Lopez covers on issues 186-189, and 196-198) which are quite nice.
Particularly when he was preceded by several issues of Neal Adams covers. Garcia-Lopez's work then is certainly comparable to either Adams or Buckler who were doing series covers at the time. As you say, Lopez did nice layout and design, and detailed rendering on these covers. And while distinctly Garcia-Lopez, were consistent with the styles of other Superman cover artists of the period.

I guess it's just the purist grumpy old man in me, who has a deep affection for the Swan/Anderson art team, and theirs is the quintessential Superman for me. The one exception to that for me is Neal Adams' rendition.

But on closer examination, I have to agree Garcia-Lopez's version is more consistent with the visual standard of the time than I'd given him credit for. While also adding his own original twist, and that's a tough tightrope to walk.