Luis' apartment is in the perfect location in Trastevere. I actually lived just a block away when I was studying abroad in Rome 3 years ago and I highly recommend the area whether you're visiting for a short or long time. The apartment itself is also very cute, and looks just like the pictures provided - a nice open courtyard right out front is a nice touch!
Luis also could not have been more helpful. We got in very early around 6am and he was still there to meet us at the apartment on time and made sure to show us everything we needed.
Only thing to note that we wish we had known is that Rome in the summer can get extremely extremely hot. Since the apartment did not have air conditioning, we unfortunately were not able to sleep well at all because of the heat.