Go to Rome and stay at Luca's!!
I would wholeheartedly recommend the flat as the perfect location to explore the city from. Luca has thought of everything; the flat is clean, well-equipped and comes with lovely little touches (bottle if wine on arrival, a spare toothbrush in the bathroom) that make it as good as a hotel...but better! It is within walking distance of everything you would want to see, but still nice and quiet. Of course, I must also mention the piece de resistance...the roof terrace! The only word to describe it is 'magical'.
Luca was also an incredibly helpful host; always at the end of the phone if we needed him, for any problems, but also just tips and recommendations. He accommodated our request for a late check out without any problems at all. We will go back!