1. Size / Portable, about 7" x 17" x 24"
2. Agility, better maneuverability around cars and obstacles
3. Speed, can go >40mph, most of the time you only need 15~25mph
4. Hands free, can carry stuff
5. Wheel size is 16" and up (better than scooters with small wheels)
Downsides:
1. Weight, 40lbs and up (my current one is 65lbs)
2. Electric only
3. Safety - if it cuts out, your falling off (has yet to happen to me)
4. No exercise like a bike (I became much weaker after I stopped riding my bike)
5. Expensive (starts ~$1300 for basic, likely will want to spend $1800-$2400)