I write performance critical software for a living (industrial image recognition) and I often try to squeeze the last few percent out of an algorithm. But even in my case the by far largest part of code I write is not performance relevant at all. And there I prefer terseness and readability over performance. Yes, there can be some cases where I have to switch to a more efficient version later, because profiling shows a bottleneck where I did not expect one to be. But in my experience this has never been too big of a problem to sacrifice readability from the beginning in all places.