I bought 2 DF Glow D Model OS discs in hopes they would replace my 400 D1. First off, feel. The DF Glow is a stiff plastic, like 750, but with sharper edges. That will likely get better as the disc gets seasoned. The grip feels like an unpolished D1, nearly the same depth and rim feel but more "edgy". Out of the hand, it flies and glides great. I think there's more glide there than 400 D1s. The disc slightly flips up during the first 1/3 of the flight, rides flat during the middle of the flight, then fades hard with skip during the last 1/3 of the flight. It is not a D1, nor does it claim to be, but it is a great flyer for average to advanced arm speed. My typical drives are around 330-350 with some bombs going 380-400. I can consistently hit 330 with this disc. It is not as comfortable to throw or feel as pure as a D1, but it does fly great and glides another 20+ feet over a 400 D1. I think if a DuraFlex soft or DF Grip comes out, it'll be perfect. After some time with this and some wear, I can only see this flyer getting better and longer. Check out the video of this and other ACE line discs at: https://youtu.be/_VsLumGQMr0