Frank & Soledad's place was great! The first night we stayed just a floor above what we had originally booked and then transferred to the booked room. Both rooms were great -- 5th floor room had a comfier bed; 4th floor room was larger with a small balcony.
The location was perfect as it allowed us to catch a train clear across town and also walk to/from the main terminal for arrival and departure.
Frank was very responsive leading up to our arrival and even took time to show us all the must-sees on a map. He was extremely helpful.
We walked to all the major tour spots (except Vatican--that's where the train came in handy) and always found neat neighborhoods on our walks back to the room.
I'd highly recommend for anyone wanting to walk/explore Rome and also have an ease of access when first arriving. Far, far better of an experience than staying in a hotel in the city center.