I don't use Launchpad but I can say, for me, Spotlight sucks! It decides at random times not to complete. I have it set to show apps only. I don't want it to find other things. But quite often I'll press Cmd-Space and type something and it won't find it. For example I just tried "pho" and it did not show Photoshop (which is on my system) but did show stuff completely unrelated to apps and I double checked, I only have apps selected in the Spotlight Search Results section in settings.