Andreas was a wonderful host, and I highly recommend his apartment. It is very close to St. Peter's, Castle St. Angelo, a 24 hour market and the 64 bus which takes you anywhere you need to go if you don't want to walk.
Some things specifically for Canadian and US visitors: (no slight to Andreas at all, this is because Canadians and Americans assume things will be the same as we have then at home. This extra information will (hopefully) reduce the complaining and ward off any potential complaints:
This is an Italian apartment. It has a stove, microwave, and Nespresso but you don't get a kettle, oven or toaster. The washer/dryer is a European all-in-one: unless you're used to it, you'll find laundry to be frustrating. Consider a nearby laundromat instead. And no long showers: quick washes will better ensure enough hot water for everyone to bathe. Bring more than one universal electrical outlet converter. One for the bathroom; one for the bedroom. Andreas leaves clear instructions (just remember that the "air extractor " is just the "above-the-stove air vent". The front door has four tumblers; you have to turn the kept four times to unlock or lock it. (Practice with the door open and you'll see what I mean). And for those going green: Use the lower water toilet flush (smaller circle) option before using the larger one.