Police spotting (junction watch)

Other than they both have two wheels, of course. In terms of road presence, acceleration, speed, respect from car drivers, motorbikes are closer to cars

Good to ride a bike like a good scooter driver,
Pass traffic right to overtake or get to front at lights.
Ride in traffic stream

They're more like bikes in terms of space on road, vulnerability of rider, exposure to weather and recommended riding technique.

Also, like bikes, more fun than car driving, being in the world better than in a box in the world