Thanks for the replies.
I figured what you said about Alfred simply passing the command to the Finder might be the case, but I thought there might be was some kind of indexing issue. I seem to remember that, at least in times past, Spotlight and apps like Alfred kept separate indexes of items on the drive. I thought maybe index corruption could account for slowness or bad behavior.
Anyway, I'm running an iMac with 8 gigs of RAM and a 1 TB Fusion drive. Memory pressure doesn't seem to be a problem as iStat Mini is saying I'm only using about 21% memory during this testing.
I'm not running Pathfinder or any other Finder replacements—just a few things like Default Folder and Moom.
Any other thoughts?
I did your test, and launching an app the second time, after launching it once and then quitting, is indeed faster.