benjammin - my experience is that newer cast iron is rough as anything but old is smooth (pre-seasoning). I have seen some old iron that is rough but it was not well made. I do think it is made more smooth by seasoning. Here is a photo example:

http://blackirondude.blogspot.com/2008/05/old-cast-iron-vs-new-cast-iron.html

I mainly have old Griswold and a couple Wagners but I do have a couple that I'm unsure of the mfr and they are older and smoother as well.