Let's say it is 0.7 mm of runout measured on the outside of the roller. For the moment I'll guess it is uniform across the width of the roller. That is equivalent to 0.028" TIR. I'd say that Qualcast would, or at least should, be thoroughly ashamed of that. However note that the cutting reel is halfway along the wheelbase of the mower, so the bedknife only moves vertically by half the amount of the rear roller runout. I expect that the resulting grass height undulations of about a third of a mm peak-to-peak would not disturb anyone but a bowling green supervisor.
In other words, I agree with you: try it for a while to verify that it is pretty much undetectable in terms of grass surface-evenness quality.
