Do you think he did so well because his skill set is unprecedented? Or because batters have never seen him before?
Dice K was sic at first too. Teams figured him out now he's mediocre at best.
There are two things at work here: 1. He did pitch against the Pirates, and for that matter no one had any of his tendencies down (that's not to discredit his stuff) and 2. He is a lot more refined than any recent new pitcher. He spots his pitches pretty well, and to be honest, he'll come back down to Earth a bit at some point, but his stuff is probably the most refined of any pitcher in the past 25 years. Top picks tend to get overrated a ton, but in Strasburgs case, he doesn't stand out because he throws hard, rather because he's refined.