For some reason Spotlight became less responsive (maybe it's FileVault2). I tried Alfred and I love it.
What I like about the powerpack is to see contacts (from address book) without having to open the address book app.
Adding extensions are nice. I use Wolfram Alpha and a backup workflow I made. I chose to copy certain files (bookmarks, iTunes Library, etc) to Dropbox folder. When I want to back it up, I just type Backup Workflow and that's it.