It's really snappy, unlike every other alternative I've tried, and has some good base capabilities, but the extensions store (and how easy they are to write) is the killer feature.
Asking as a long time Alfred user. I've looked at Raycast, but can't really figure out what it does that Alfred doesn't.
The UX is just nice, and there's lots of little things to like. Result context menus, quick configuration changes, system control, window management, etc. I can type things into Raycast and can reasonably expect something nice to be suggested, e.g. "pi * 6", "1 month", "1 month from now", "sleep displays", "left half", "schedule", the list goes on.
I'd suggest trying it for a day. If you don't like it, switch back.
I use Dropbox to sync my Alfred setup (Config, workflows and related files) between 3-4 computers and paying $8/month just for that is a complete no-go.
Config is stored at ~/Library/Preferences/com.raycast.macos.plist
Everything else is at ~/Library/Application Support/com.raycast.macos