I just want to update you from what I said a post ago. I had a chance to throw a friend's fresh G PD today and compare to my ~1 month used S PD. The G PD is significantly less stable if you have power. My S PD has zero turn, I have never ever turned it a smidge. It fades out on me at 350', and I can throw speed 12-13 stuff up to 400'. It's very beefy, and holds a hyzer.
The G PD has turn to it when I throw it as hard as my S PD. I can hyzer flip it for great straight shots. When released flat it drifted right for me. I could trust it at 300' much more to go straight, as a hyzer flip or a slight turnover. However, this was when I was overpowering it into a turn and throwing it low (like 6'), and it would land dead straight. I still stand by what I said earlier that if I wanted to throw dead straight 300' I would rather throw a disc I didn't have to overpower so much, as speed 10 is far too much for that distance to me, barring an extreme ceiling restriction or wind. I don't know how the G PD would act if I gave it 300' of power rather than overpowering it and letting it only go that far due to height. I would still recommend the Teebird suggestion at 300'.
But, the G PD was significantly different enough from the S PD for me to want to update this. It is a very nice disc.