No it's not! Plus, you'd get to see the replacement targets while you're holding the keys, so you'd be more confident about the final result.

Just give Ctrl-D a try for a couple of days.. It's a total different user experience compared to the traditional find/replace method.

Do you mean it's a lot of work to type in that prefix? Because vim automatically inserts it for you when you enter command mode while something is visually selected. A making a visual selection is very quick and easy.