Lately, I found out that Application Launcher also features all the functionality I use from KRunner.
In my particular experience, Application Launcher is snappier at first launch and also returns results rather quickly. For me, this begs an obvious question.
What's the use case for using KRunner over the Application Launcher?
So far I've noticed that pressing Enter on the Calculator results makes the entry be copied on KRunner, but this does not happen for the Application Launcher. I'm certain there must be something else to it, otherwise people would not be using it (even I found myself using it from time to time, but could not understand why).
Krunner is better at displaying longer search results. The launcher truncates anything longer than 1 line. Dictionary definitions are an example.
Krunner also keeps what was last typed in, which is very useful if I'm adding up a bunch of numbers, or if I need to switch to a different application before using the result.
Yup, that's more like it. I hadn't realized about the first paragraph.