Yeah, that's totally what you'd do, in either editor. But my broader point is that there are situations where the immediate feedback and interactivity of using multiple cursors is valuable.
How is immediate feedback and interactivity going to help if the changes span more than one page? If you are going to extrapolate(looks fine on this page, must be fine elsewhere), you can very well extrapolate from a smaller sample size(run :s/some_crap/some_other_crap/gc, check one or two occurrences, then do 'a' for all).
One can always stop typing and simply scroll down and check.
I've tried to like it and believe that instant feedback is actually useful but no. I couldn't.