My wife and I rode around Rome for three days on a Piaggio MP3 250 and thoroughly enjoyed it. I grew up in Italy and go back to ride with my childhood buddy when I rent a motorcycle, usually a BMW for some reason, for cross country rides together he and I. Last year my wife and I wanted a few days alone together exploring Rome and the MP3 was just the ticket.
It was excellent on the rouigh cobble streets and crossing tram (streetcar) rail lines. It enabled me to keep up with the local maniacs riding the same streets on two wobbly wheels. I am not a fan of the complex technology of the MP3 as a daily rider for myself but I can see why this machine is so popular in crowded urban areas of Europe.
We took it out into the countryside and rode the Alban Hills (Castelgandolfo area) and buzzed out to Ostia Antica the old Roman port city. It kept up fine with main road traffic at 70 plus mph (110 kph) with speed to spare even two up.
However we didn't ride it on original Roman roads though I'm sure it would have done fine...
It was excellent for getting around the alleys of Trastevere at night, with powerful headlights and it was easy to park on rough streets by simply locking the wheels. Even sideways on slopes! I had to be careful unlocking it!
I did not lock the wheels at traffic lights because I found the practice rather off putting and contented myself with putting my feet down, in conventional style.
And it was as easy to ride splitting traffic as any two wheeled scooter. Great fun!