Your wrong, follow the thread url. The hard sigop limit is the way to fight such attacks. All times are for worst case blocks than can be used for attacks and the same computer to make the comparsion fair.
I don't have time to follow that thread. So this is the worst case scenario? If we assume that this is true, then then Segwit seems pretty good. Added capacity without an increase in the amount of hashed data and no additional limitations. Did I understand this correctly?