What I dislike immensely is that even if your hard drive is close to exhausted, Apple thinks nothing of silently downloading the "Install MacOS NextWhizBang" app (several gigs) into Applications behind your back, pushing you under the minimum free-space margin needed to swap out your virtual memory. This happened to me within the past month on my "virgin OS" externals, turning a simple bootload into an excruciating ten-minute slogfest, followed by another 15 minutes wasted time hunting to figure out why everything was running at a snail's pace. I finally created a folder of the same name as the app to stop it from continuing to download every time my back was turned.