Shortcuts often don't remove the need to take your hand off the mouse, so the cycle time can be slower. As the OP says, when you don't need to do bulk text entry the keyset can work better, especially if your editor is tuned fot it (as NLS was).
I use a left hand controller (an old razer n52 nostromo) for video games and it really helps, though sometimes you have to spend some time configuring it. works for normal text editors too.