I carry both an FLX-Avenger SS and a Champ Sidewinder.
FLX-Avenger SS is surprisingly long. The plastic is awesome, and the mold is very consistent. They start out pretty much straight or a tiny bit of turn at 350' of power. But after a couple tree smacks they settle into one of the better turnover discs out there. They can be finessed into a hyzer flip or an S-Curve. Or you can torque them into a turnover dive (yes, dive) for downhill turnover shots (#9 at my home course, The Sinks). Like any out-of-the-box turnover driver, they're nose-angle sensitive. A good rip with some nose down will make it crash and burn hard. Be forewarned that the Pro-D Avenger SS is a roller out of the box. The flippiest driver I've ever thrown at max weight. Never thrown one in Z plastic.
Champ Sidewinder - I've now owned two, both red 175g. One was stable out of the box, and beat into a nice turnover driver. The other one was very flippy straight out of the gate. The Sidewinder is less shot shape-able, but more reliable than the Avenger SS, I guess. Throw it between 80-100% and it does the same thing. Hyzer it and it'll S; thrown flat it'll turn over and hold it for the majority of the flight.
Both great discs. I think if I had to choose between the two, I'd go with the Avenger SS due to its ability to perform a variety of shots, and because of how consistent the mold from disc to disc has been for me. And because the plastic is awesome.