This is certainly one of the best ways to enjoy Rome
I wanted to show Rome to my 80 years-old grandmother. However, Rome is large and walking from sight to sight (or from subway and bus stops to sights and back) will quickly exhaust even younger tourists. Having no previous experience with electric minicars we decided to give it a try. It was a complete success. The tiny cars provide perfect mobility and flexibility. On the one hand, those are kind-of cars, so you can use them to go larger distances via normal roads (e.g. from St. Pietro to Colosseum).On the other hand, those are also kind-of pedestrian vehicles, so you can use them to enter (or get maximally close to) the pedestrian areas.
Next time I go to Rome I plan to use them again (and this has nothing to do with me being lazy to walk, I just found the concept really fun).
The car is smallish, but it will fit two average (or even slightly obese) adults. It is a bit inconvenient to use the pedals, at first, and a bit scary to drive on the streets, but you get used to this.