Have you measured your smooth rod straightness, so that it could be presented in any clear way ? If i roll my rods on a glass plate, yes there is some really minor movement, but in my oppinion no major fault.
I do have a dial indicator so that i can get, maybe, somekind idea of the play when turnin the rods on a glass, but what would be the minimum "goal" that i could accept to be straight enough ?