I have to throw my 2 cents in here. Let's face it, a lot of really good reps end up getting PIPd somewhere along the way, especially if you're simply not favored by your jackass DM. Say you want to leave really badly (who doesn't??); want a package but don't know if you'll ever get it, and can't take it anymore. Personally, once I got on my first and only PIP (after more than 13 successful years with the company. Imagine that), I didn't fight it. I didn't fight for a job I hated; just decided to do the hard thing and let it ride. If I quit, like I REALLY wanted, I would've had no severance and no unemployment to help out while job-hunting (which, btw, does take a very long time these days). You have to have some intestinal fortitude to go the route I did, but I basically ignored/defied the PIP, reported to HR that the mgr who put me on it was a liar, and gave the details (b/c, yes, there was some seriously shady lying going on); of course HR pretty much sided with mgt (but didn't matter at that point...I was getting out one way or another), and just continued working normally until the PIP came up and I let myself get let go. I got severance and was also able to collect unemployment.
Not for everyone, I know. Many people couldn't fathom letting that happen, but I did what I had to do, both for my own sanity and for the extra cash I was going to need to start over somewhere else (outside pharma!!). Just a thought folks. Future employers don't need to know what happened; will probably just assume you were laid off anyway.
It's a difficult thing to let happen to yourself, especially if you've been a pretty stellar employee your whole life, and you hate to think the company or mgr thinks they got the best of you, but honestly... I didn't feel that way so much b/c I let the DM know that I did this thing MY way, and that I was happy with the outcome. And I was.
Do what you have to do. It's not that big of a deal in the grand scheme of things.
My health (mentally and physically) improved dramatically after I was gone. Good luck to all who want out. I feel for you all. Peace.