He is lightyears ahead of Martins technically, that's true. And creatively too.
But Martins is way ahead of him in goalscoring, pace, strength, shooting, dribbling, and last but not least he's much younger.
Fair enough, but I think he'd get very close to the same number of goals as Martins if he was played a bit further up front.
In short, Gudjohnsen can do what Martins can do but not the other way round. Gudjohnsen is by far the better, rounded player.