Short story: If it's available, book it before someone else does. :)
Long story:
Aldo is a great host, and we really felt he did everything he can so we could enjoy the stay. He and Paola were really attentive to details, small things that make your stay more than good - perfect.

The apartment is in the very center of the city, near Colosseo and Capitolium hill, and not far from Termini station. You can easily walk everywhere and save on transport - we used it only twice during our stay.
The place is very spacious, light, looks great and feels like a proper home. Everything is new and clean.
It is quiet, because the windows effectively block the noise.
The bed is big and comfortable, perfect for a refreshing sleep.
The shower has hot water - plenty of it, provided by a gas heater. This may seem like a minor thing, but keep in mind, that many apartments have an electric heater, so the water may be only warm, and the supply is limited, so you would have to wait before it heats again.
There's everything you may need in the kitchen and in the bathroom - like a shampoo, shaving cream, basic household items etc.

On top of that, Aldo is very nice person, he was always available for our questions, and we felt like he really cares about our comfort.

Overall, it was a great AirBnB experience, probably the best, so I would strongly recommend staying at Aldo's place.