I was there so I didn't have the benefit of a good view of the strike zone or instant replay. That being said...
Don't know if it was nerves or what, but he seemed to lack command. Threw a lot of pitches--his pitch count was in the 70s or 80s after 4 innings IIRC (actually 87 according to ESPN)--and seemed to go to full or near-full counts on most batters, even though he "only" walked 2. I'd be curious to hear what others thought of the dinger-fest. It looked to me like he just left the ball over the plate. From where I was sitting, they didn't seem to be great pitches.
Stuff-wise, he reminded me a lot of Springer (with the addition of a change).
Edited to add: just noticed that pravata's (excellent, as usual) recap is up already. Some useful thoughts about Hirsh if you haven't seen it yet.