Within reason, the way it gets from one end to the other shouldn't make a difference in handling, provided the the dropouts are in the same place relative to the steerer. If the rake is the same, the length is the same, and the trail is the same, whether it's straight or curved shouldn't matter at all.
What I can tell you from experience, is that there can be a difference in ride, however how much is attributable to straight vs. curved, and how much is attributable to construction technique leaves a lot open for argument, speculation and interpretation.
Fork leg profile can make a difference in handling to the extent of how much side-to-side movement it allows while cornering. My bikes with Wound Up forks (round fork legs) both seem to track better in corners than my two bikes with the more common thinnish-flattish profile (Time Carbon/Vectran and Easton EC30). Imagine the way a plastic drinking straw is laterally stiffer than a plastic butter knife.
Anyway, that's my experience with carbon forks. It may or may not apply to steel ones.