I've been with Pinnacle since April 2005 as a Customer Service Rep/Ramp Agent (working to get on as an F/O). I've heard all the rumors both internally and externally and every single one is different. My personal opinion is just don't listen to them, there are too many "watercooler quarterbacks".
I have a few college buds that fly for 9E now, two are captains, one a F/O. They really seem to enjoy flying the "Canadair Reset Jet" and are overall happy with their job. From what I can tell the upgrade time is about 2 years.
I love Pinnacle. I would apply.