We stayed at this hotel for two nights during a two week car trip from Pompeii to Venice. We wanted something that isn't too expensive, has free parking, and gives us easy access to public transportation. Arcadia met all three criteria: It's relatively inexpensive, has a ton of room for parking, both outdoors and in a gated basement parking garage operated by the hotel receptionist, and the bus to Anagnina metro station is right outside its door. Indeed, Anagnina metro station itself has a ton of parking space, a section of which is even free (at the north eastern end of the outdoor parking lot, just beyond the fence). Get a cheap public transportation day pass from the friendly tabachist down the street from the hotel and you can enjoy Rome stress-free in no time at all.
The hotel itself is fairly bland. Internet access is not free (as is the case with most Italian hotels in this price range), the breakfast is standard, but there is a large PAM supermarket right next door (it's on the back side of the same building), and an athletic club with a public park and a pretty good (and not busy at all in the evening) restaurant a couple of blocks away, so you have some flexibilty in terms of your dining options if you don't plan to stay in Rome all day and all night.
The neighborhood is working class, but might look rougher than it really is due to the graffiti-infested public parking areas not far from the hotel.
All told, Arcadia is not a hotel we will remember for long, but it was just right for us, because it freed us to remember everything else.