I used to have one of those! I built it using a cheap 49cc conversion kit.

Honestly I'm not sure it was purely better: I had to pedal a bit before engaging the clutch to not stall the motor. It also became hard to breathe when stopped because of the fumes from the engine idling.

Was kinda fun to ride around though, but they outlawed them here. Guess other bike path users don't like smelling burnt oil...