Christian's apartment is at a really awesome location and we (2 couples) had a great time in Rome. Its 3-4mins walk to the Piazza Navona and just a bit more to the Pantheon. The smaller streets parallel to the main street also offer some great options to eat.

We didn't meet Christian but he arranged for someone else (I guess his neighbour) to take care of the checkin and it all went well.

The apartment itself has huge common areas, but the furnishing we felt was a bit bare. The room facing the road can also be a bit noisy at night.