When choosing a frame, consider this:
- size (typically stated in diagonal motor distance)
- motor mount size
- size/shape of cargo area
The frame size determines how large the props can be, how much space for payload is in between, and how stable the quad will fly. A larger quad (e.g. 135mm motor diagonal) will fly calmer and more stable than a 80mm quad.
Most micro frames can be used with either 6mm, 7mm, or 8.5mm motors. On some frames, you can change the mounts to fit a different size motor.
An H-frame provides a better cargo area than an X-frame.
X-frames tend to be lighter and crash better.