I applied in August and snagged a cancellation at Nashville by just checking constantly - was worth it even though it's not my home airport. Total time between first application through process complete-approved was 16 days. I know people who have been waiting for the better part of a year for GE/Pre.

I spent seven minutes in total at the Nashville Enrollment Center. Took my picture, looked at my passport, and they didn't say anything other than "you're all set!"