Just my opinion. The Edge is the easiest to 3D. The 300S has a slight amount of pitch coupling in knife edge, but is marginally easier to deliberately stall than the Edge. The 300L has more pitch coupling than the Edge and the 300S, and will deliberately stall better than the 300S. It will also inverted Harrier better than the Edge or the 300S.

All will hold clean lines, and all are easy to fly and land.