The Infinite Discs Tomb is flat and beaded and will hold up to a ton of power. It is stable enough for forehands and backhand it will hold a straight flight into a moderate headwind. It is great to use off the tee or putting into a headwind and you need to trust the disc to hold up without being too overstable.
D-Blend plastic is a basic, inexpensive plastic blend (compare to Innova DX plastic). It has good grip and medium softness. It is more easily beat-in when used than premium plastics, but it preferred by many players for putters and mid-range discs where grip is important.