We highly recommend Luca's place. It is very well located: Trastevere is basically at your doorstep, and Campo di Fiori some 30 min away. An amazing Giolitti Gelato shop is just around the corner (and it is much better and cheaper than the one in the city center). The fantastic Pizzeria Remo as well as a Trappizino are also around the corner (the latter is a very nice place to have a beer and a snack). We enjoyed Testaccio and the fact that it did not feel touristy at all. We especially liked the Piazza Testaccio, a little square a few blocks away from the house, where locals sit after hours in park benches and have drinks & food from nearby bars & pizzerias. We hope to visit again!