I think they handled it pretty well despite the shitty premise. The “duel” would have been less than 10 seconds if it were in film or TV and it sewed the seeds of Vader finding out he had a son. Though he could have found that out some other way such as having looking at Luke through a security recording and seeing his old lightsaber and putting two and two together later on.
Meh, it was awful. Vader’s quest for the pilot who destroyed the Death Star in the original Marvel run was pretty epic. Through multiple issues he hunted down any leads he could find to discover the name of the pilot before he finally succeeded:
Very cool but a bit of a continuity snag in hindsight as Vader’s reaction isn’t quite what it would be considering the revelations of certain film yet to be released at the time.
Well, there is also Dark Horse’s version of how Vader discovered Luke’s identity. In that story, Vader goes into a batshit homicidal panic attack when he learns the news.
I think I prefer Marvel’s original version.