Fast software, the best software

I love fast software. That is, software speedy both in function and interface. Software with minimal to no lag between wanting to activate or manipulate something and the thing happening. Lightness. Software that's speedy usually means it's focused. Like a good tool, it often means that it's simple, but that's not necessarily true. Speed in software is probably the most valuable, least valued asset. To me, speedy software is the difference between an application smoothly integrating into your life, and one called upon with great reluctance. Fastness in software is like great margins in a book - makes you smile without necessarily knowing why. Nothing to add.