When comparing Spotlight vs Quicksilver, the Slant community recommends Quicksilver for most people. In the question“What are the best app launchers for Mac OS X?” Quicksilver is ranked 3rd while Spotlight is ranked 5th.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Native to OS X
Spotlight comes packaged with OS X and iOS.
Pro Intuitive
Pro Easy-to-understand noun-verb paradigm for creating tasks
Pro A lot more powerful than Spotlight
Pro Makes it really fast to do a lot of actions
There are customizable triggers and capability to execute multilevel commands - e.g. launch terminal app, give the location of script and supply parameters for the script with one command.
Pro Vast extensibility via plugins
A lot of different plugins for browsers, file systems, mail clients, etc.
Cons
Con Limited customization
Allows for very little customization, not theming, and no custom scripting.
Con No longer launches applications at all in Sierra
After updating to Sierra, typing an application name in Spotlight results in "No Results" or random wikipedia matches. True even after reloading com.apple.metadata.mds.plist and adding/removing "Macintosh HD" on the "Privacy" tab. Launchpad still works.