Premium Processing vs Regular Processing

Lately I've been encountering quite a number of people who have filed for various visas under regular processing, and saying they're waiting 7, 8, 9 months, and still no answer.

Some have said they filed last summer, and still waiting on an answer.

That being said, after using regular processing for multiple prior O-1 visas, I'm starting to look at filing for Premium Processing.

From what I've read in these groups, some are getting approved after getting an RFE, and some are getting straight approvals.
What's been your experience?