No, you said that hight being the reason for Karlovic' serve being good somehow takes away the fact that is actually better than Milos's and I said that that doesn't change a thing. If you're a 5'2 and a great serve motion, you're serve would stil suck. Look at Almagro or Tipsarevic. They have a great serves for their hight, they make the most of it, have a better serve motion and 'tennis skills' whatever that means, but Ivo's serve is still better. Reason for him having a better serve don't metter, it's better (more effective), period.
Of course it changes everything, If Milos was the same height as Ivo his serve would be even better cause he has more skill to it than Ivo's, it's skill we are talking about here when it comes to serve, not height, there are quite a few servers out there with better skill than Ivo, if they were the same height as him they would all be better, they are all better at their own heights, but because they are less tall they aren't quite as good in the stats, Ivo's stats look better cause he's taller, not cause he's got the skills.