An example of 'both' is Apple's iPhone. Steve Jobs was adamant about how it should look, feel and work like. At the time of the introduction in 2007 (I believe), many features did not actually work. So each time he talked about a certain feature, Jobs took another iPhone (they all looked the same of course) to demonstrate it, with that particular feature already running. Staff was nervous as hell. All glitches were solved when the iPhone (as Jobs had showed to the public for the first time) came to be sold. IMO, that's a good example of vision-induced engineering. Jobs didn’t take “impossible" for an answer if that stood in the way of implementing his idea what a product should be like.