I don't have a vespa but I have a Yamaha Majesty. It's 400cc and a heavy bike. I just love it. My midlife crisis purchase. It's powerful enough to be on the road and not feel like I'm gonna be run over. Plus it's fun to pull away from a stop light and accelerate way faster than the cars.
If you don't have your motorcycle license take the MSF (motorcycle safety foundation) course offered in your state. Even though you learn on a motorcycle it's worth the price and time to take it.