ummm.... the best way i can describe it is it just FEELS different. just crack a piece of code and select something and hit CTL D. since you somewhat manually select each instance, you know 100% what will be changed. plus, no dialog box, you're not entering a serach, entering a replacement, then hitting go.... you're multi selecting and multi editing.

i only ever use CTL H if i want to find and replace across multiple files these days.