This place is awesome! Beautiful apartment on the first floor. Lots of space, very clean, amazing shower, I can't say enough about how much we liked the apartment. I wouldn't mind purchasing the apartment from Marco and staying there forever! Host was very responsive. Greeted us with a bottle of wine, which worked well for us when we decided to dine in one night with takeaway food. I would say don't hesitate at all about the place, you will love it. There are several restaurants within one block radius (average price of one item was 10 euros). Umbrellas were included in the apartment for rainy hours, which we did use. One thing though, the toilet is positioned slightly closer to the sink, so if you are particularly large, you may feel slightly cramped, but it really isnt that big of a deal...everything is super clean, so just hug the sink if you are Michael Jordan or a few standard deviations more rotund than the average American. Oh there are a bunch of tourist resources at the place. They had various books, maps, pamphlets, everything you need to get around in rome. Be sure to get the 48 hour metro pass if you are staying for that long, I think it was worth it!
Location was within walking distance from Roma Centrale station...around 20-25 minutes walking. Host tells me a tram is also available, but the trams looked a bit crowded when I saw them, and I don't know what their schedule is like, so never used them.
This place is also 10-15 minutes walking distance from the nearest metro station and is extremely straight forward to walk to...literally just straight in one direction. A tram should be able to take you there as well.
Additional tip for ladies: while it is obvious to watch out for pick pockets, another thing to watch out for are butt grabbers. My girlfriend claims someone grabbed her butt while we were in a rush to exit a packed bus before it leaves. While I do like her butt, I'm a bit disappointed that I didnt get similar treatment. Regardless, watch your butt in crowded places.
Overall, great place to stay, extremely clean (and I have stringent standards), extremely nice place, very responsive hosts, and nice hosts. It could have been a bit closer to the metro, but the comfort of this place more than makes up for it. I would stay here again!