Like Tanner said, if anything had been heavily modified, they would have closed the ride down for a while to make the changes. What exactly happend to SoB to make it smoother? They could have worked on it at night in the dark to make some changes, but I doubt that. Mabye just certain sections of the track were replaced with new track to make it smoother? I dont know, but for me, SoB was definitly worth a few bumps in the track now and then. Next time I come I'll see if the track is still smooth and less rough like you said.
I hope they keep the SoB nice and smooth, but if they dont it's no big deal either.