NS1 started out having standard "letter" style hotkeys - "b" for Build, "v" for Advanced, etc. Later it changed to use a "grid" system by default. This way it doesn't matter what the name of the button is, the hotkeys map to the keyboard physically (see attached image).
Here's a video talking about the "grid" system (skip ahead a bit):
My impression has always been that the grid system is superior for speed and ease of use, but that the letter system is easier to learn in the first few minutes and is also the legacy system (Starcraft 2 defaults to the letter system but added the grid system as an option). I believe the grid system came as a user mod to Warcraft III but has yet to be adopted broadly.
Do you guys have a preference? The game supports remappable hotkeys of course, so this discussion is only about choosing a default the game has loaded.