The E plastic ones I have are pretty overstable, but not ridiculous. They're also a few years old. They'll hold a straight line before fading hard. I've heard the more recent runs are more overstable than them, though. The S plastic ones start off more overstable but break in to hold a straight line for a bit. AFAIK, the S plastic ones are OOP.
FWIW, I throw them because I have them. If I were going to start over and buy new discs I'd probably go with Z Preds.