IIRC redraw doesn't happen until the sort finishes, but I use Excel as little as I can get away with, so I don't have a recent memory to rely on. That said, at a guess, reordering rows of equal height (and otherwise with no non-default properties) is probably mostly just rearranging pointers - why bother keeping row index associations intact, when the only trait of any row is the values in its cells? - while reordering rows of varying height might involve a lot of copying, or otherwise significantly more complex shenanigans, to make sure data and row properties stay properly associated.